1
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Heitmann T, Liao G, Ernst G, Poslusney M, van Kralingen T, Li Y, Masi M, DePasquale M, Buchler I, Wei H, Carr GV, Shlevkov E, Lu M, Jessen H, Barrow JC. Identification and Characterization of a Blood-Brain Barrier Penetrant Inositol Hexakisphosphate Kinase (IP6K) Inhibitor. J Med Chem 2024; 67:13639-13665. [PMID: 39096294 DOI: 10.1021/acs.jmedchem.4c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2024]
Abstract
Inositol hexakisphosphate kinases (IP6Ks) have been studied for their role in glucose homeostasis, metabolic disease, fatty liver disease, chronic kidney disease, neurological development, and psychiatric disease. IP6Ks phosphorylate inositol hexakisphosphate (IP6) to the pyrophosphate, 5-diphosphoinositol-1,2,3,4,6-pentakisphosphate (5-IP7). Most of the currently known potent IP6K inhibitors contain a critical carboxylic acid which limits blood-brain barrier (BBB) penetration. In this work, the synthesis and testing of a variety of carboxylic acid isosteres resulted in several new compounds with improved BBB penetration. The most promising compound has an IP6K1 IC50 of 16 nM with an improved brain/plasma ratio and a favorable pharmacokinetic profile. This series of brain penetrant compounds may be used to investigate the role of IP6Ks in CNS disorders.
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Affiliation(s)
- Tyler Heitmann
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Gangling Liao
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Glen Ernst
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Michael Poslusney
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Thomas van Kralingen
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ye Li
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Megan Masi
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Michael DePasquale
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ingrid Buchler
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Huijun Wei
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Gregory V Carr
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Evgeny Shlevkov
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Mengsi Lu
- Institute of Organic Chemistry and CIBSS─Centre for Integrative Biological Signaling Studies, Albert-Ludwigs-University, Albertstr. 21, Freiburg 79104, Germany
| | - Henning Jessen
- Institute of Organic Chemistry and CIBSS─Centre for Integrative Biological Signaling Studies, Albert-Ludwigs-University, Albertstr. 21, Freiburg 79104, Germany
| | - James C Barrow
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
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2
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Khan A, Mallick M, Ladke JS, Bhandari R. The ring rules the chain - inositol pyrophosphates and the regulation of inorganic polyphosphate. Biochem Soc Trans 2024; 52:567-580. [PMID: 38629621 DOI: 10.1042/bst20230256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/29/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024]
Abstract
The maintenance of phosphate homeostasis serves as a foundation for energy metabolism and signal transduction processes in all living organisms. Inositol pyrophosphates (PP-InsPs), composed of an inositol ring decorated with monophosphate and diphosphate moieties, and inorganic polyphosphate (polyP), chains of orthophosphate residues linked by phosphoanhydride bonds, are energy-rich biomolecules that play critical roles in phosphate homeostasis. There is a complex interplay between these two phosphate-rich molecules, and they share an interdependent relationship with cellular adenosine triphosphate (ATP) and inorganic phosphate (Pi). In eukaryotes, the enzymes involved in PP-InsP synthesis show some degree of conservation across species, whereas distinct enzymology exists for polyP synthesis among different organisms. In fact, the mechanism of polyP synthesis in metazoans, including mammals, is still unclear. Early studies on PP-InsP and polyP synthesis were conducted in the slime mould Dictyostelium discoideum, but it is in the budding yeast Saccharomyces cerevisiae that a clear understanding of the interplay between polyP, PP-InsPs, and Pi homeostasis has now been established. Recent research has shed more light on the influence of PP-InsPs on polyP in mammals, and the regulation of both these molecules by cellular ATP and Pi levels. In this review we will discuss the cross-talk between PP-InsPs, polyP, ATP, and Pi in the context of budding yeast, slime mould, and mammals. We will also highlight the similarities and differences in the relationship between these phosphate-rich biomolecules among this group of organisms.
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Affiliation(s)
- Azmi Khan
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India
| | - Manisha Mallick
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Jayashree S Ladke
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India
- Graduate Studies, Regional Centre for Biotechnology, Faridabad 121001, Haryana, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India
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3
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Chakkour M, Greenberg ML. Insights into the roles of inositol hexakisphosphate kinase 1 (IP6K1) in mammalian cellular processes. J Biol Chem 2024; 300:107116. [PMID: 38403246 PMCID: PMC11065760 DOI: 10.1016/j.jbc.2024.107116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 02/27/2024] Open
Abstract
Inositol phosphates and their metabolites play a significant role in several biochemical pathways, gene expression regulation, and phosphate homeostasis. Among the different inositol phosphates, inositol hexakisphosphate (IP6) is a substrate of inositol hexakisphosphate kinases (IP6Ks), which phosphorylate one or more of the IP6 phosphate groups. Pyrophosphorylation of IP6 leads to the formation of inositol pyrophosphates, high-energy signaling molecules that mediate physiological processes through their ability to modify target protein activities, either by directly binding to their target protein or by pyrophosphorylating protein serine residues. 5-diphosphoinositol pentakisphosphate, the most abundant inositol pyrophosphate in mammals, has been extensively studied and found to be significantly involved in a wide range of physiological processes. Three IP6K (IP6K1, IP6K2, and IP6K3) isoforms regulate IP7 synthesis in mammals. Here, we summarize our current understanding of IP6K1's roles in cytoskeletal remodeling, trafficking, cellular migration, metabolism, gene expression, DNA repair, and immunity. We also briefly discuss current gaps in knowledge, highlighting the need for further investigation.
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Affiliation(s)
- Mohamed Chakkour
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA.
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4
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Qi J, Shi L, Zhu L, Chen Y, Zhu H, Cheng W, Chen AF, Fu C. Functions, Mechanisms, and therapeutic applications of the inositol pyrophosphates 5PP-InsP 5 and InsP 8 in mammalian cells. J Cardiovasc Transl Res 2024; 17:197-215. [PMID: 37615888 DOI: 10.1007/s12265-023-10427-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 08/14/2023] [Indexed: 08/25/2023]
Abstract
Water-soluble myo-inositol phosphates have long been characterized as second messengers. The signaling properties of these compounds are determined by the number and arrangement of phosphate groups on the myo-inositol backbone. Recently, higher inositol phosphates with pyrophosphate groups were recognized as signaling molecules. 5-Diphosphoinositol 1,2,3,4,6-pentakisphosphate (5PP-InsP5) is the most abundant isoform, constituting more than 90% of intracellular inositol pyrophosphates. 5PP-InsP5 can be further phosphorylated to 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8). These two molecules, 5PP-InsP5 and InsP8, are present in various subcellular compartments, where they participate in regulating diverse cellular processes such as cell death, energy homeostasis, and cytoskeletal dynamics. The synthesis and metabolism of inositol pyrophosphates are subjected to tight regulation, allowing for their highly specific functions. Blocking the 5PP-InsP5/InsP8 signaling pathway by inhibiting the biosynthesis of 5PP-InsP5 demonstrates therapeutic benefits in preclinical studies, and thus holds promise as a therapeutic approach for certain diseases treatment, such as metabolic disorders.
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Affiliation(s)
- Ji Qi
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Linhui Shi
- Department of Critical Care Unit, Ningbo Medical Center Li Huili Hospital, Ningbo University, Ningbo, 315040, Zhejiang, China
| | - Limei Zhu
- Department of Trauma Orthopedics, Ningbo No.6 Hospital, Ningbo, 315040, China
| | - Yuanyuan Chen
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Hong Zhu
- Department of Obstetrics and Gynecology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Weiwei Cheng
- Department of Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Alex F Chen
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
| | - Chenglai Fu
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
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5
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Bhat SA, Malla AB, Oddi V, Sen J, Bhandari R. Inositol hexakisphosphate kinase 1 is essential for cell junction integrity in the mouse seminiferous epithelium. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119596. [PMID: 37742721 DOI: 10.1016/j.bbamcr.2023.119596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023]
Abstract
Inositol hexakisphosphate kinases (IP6Ks) are enzymes that catalyse the synthesis of the inositol pyrophosphate 5-IP7 which is involved in the regulation of many physiological processes in mammals. The IP6K paralog IP6K1 is expressed at high levels in the mammalian testis, and its deletion leads to sterility in male mice. Here, we show that the loss of IP6K1 in mice causes a delay in the first wave of spermatogenesis. Testes from juvenile Ip6k1 knockout mice show downregulation of transcripts that are involved in cell adhesion and formation of the testis-specific inter-Sertoli cell impermeable junction complex known as the blood-testis barrier (BTB). We demonstrate that loss of IP6K1 in the mouse testis causes BTB disruption associated with transcriptional misregulation of the tight junction protein claudin 3, and subcellular mislocalization of the gap junction protein connexin 43. In addition to BTB disruption, we also observe a loss of germ cell adhesion in the seminiferous epithelium of Ip6k1 knockout mice, ultimately resulting in premature sloughing of round spermatids into the epididymis. Mechanistically, we show that loss of IP6K1 in the testis enhances cofilin dephosphorylation in conjunction with increased AKT/ERK and integrin signalling, resulting in destabilization of the actin-based cytoskeleton in Sertoli cells and germ cell loss.
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Affiliation(s)
- Sameer Ahmed Bhat
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India
| | - Aushaq Bashir Malla
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India; Manipal Academy of Higher Education, Manipal 576104, India
| | - Vineesha Oddi
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India
| | - Jayraj Sen
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India; Graduate Studies, Regional Centre for Biotechnology, Faridabad 121001, Haryana, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India.
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6
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Heitmann T, Liao G, de León P, Ernst G, Buchler I, Wei H, Shlevkov E, Brown D, Fitzek M, Collier M, Smith DM, Barrow JC. Fragment-Based Screening Identifies New Quinazolinone-Based Inositol Hexakisphosphate Kinase (IP6K) Inhibitors. ACS Med Chem Lett 2023; 14:1760-1766. [PMID: 38116421 PMCID: PMC10726443 DOI: 10.1021/acsmedchemlett.3c00409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023] Open
Abstract
A high-throughput fragment-based screen has been employed to discover a series of quinazolinone inositol hexakisphosphate kinase (IP6K) inhibitors. IP6Ks have been studied for their role in glucose homeostasis, metabolic disease, fatty liver disease, chronic kidney disease, blood coagulation, neurological development, and psychiatric disease. IP6Ks phosphorylate inositol hexakisphosphate (IP6) to form pyrophosphate 5-diphospho-1,2,3,4,6-pentakisphosphate (IP7). Molecular docking studies and investigation of structure-activity relationships around the quinazolinone core resulted in compounds with submicromolar potency and interesting selectivity for IP6K1 versus the closely related IP6K2 and IP6K3 isoforms.
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Affiliation(s)
- Tyler Heitmann
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Gangling Liao
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Pablo de León
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Glen Ernst
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ingrid Buchler
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Huijun Wei
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Evgeny Shlevkov
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Dean Brown
- Hit
Discovery, Discovery Sciences, R&D, AstraZeneca, Boston, Massachusetts 02451, United States
| | - Martina Fitzek
- Hit
Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, Macclesfield SK10 4TG, U.K.
| | - Matthew Collier
- Hit
Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, Macclesfield SK10 4TG, U.K.
| | - David M. Smith
- Emerging
Innovations Unit, Discovery Sciences, R&D, AstraZeneca, Cambridge CB2 0AA, U.K.
| | - James C. Barrow
- Lieber
Institute for Brain Development, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
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7
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Aguirre T, Dornan GL, Hostachy S, Neuenschwander M, Seyffarth C, Haucke V, Schütz A, von Kries JP, Fiedler D. An unconventional gatekeeper mutation sensitizes inositol hexakisphosphate kinases to an allosteric inhibitor. eLife 2023; 12:RP88982. [PMID: 37843983 PMCID: PMC10578927 DOI: 10.7554/elife.88982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023] Open
Abstract
Inositol hexakisphosphate kinases (IP6Ks) are emerging as relevant pharmacological targets because a multitude of disease-related phenotypes has been associated with their function. While the development of potent IP6K inhibitors is gaining momentum, a pharmacological tool to distinguish the mammalian isozymes is still lacking. Here, we implemented an analog-sensitive approach for IP6Ks and performed a high-throughput screen to identify suitable lead compounds. The most promising hit, FMP-201300, exhibited high potency and selectivity toward the unique valine gatekeeper mutants of IP6K1 and IP6K2, compared to the respective wild-type (WT) kinases. Biochemical validation experiments revealed an allosteric mechanism of action that was corroborated by hydrogen deuterium exchange mass spectrometry measurements. The latter analysis suggested that displacement of the αC helix, caused by the gatekeeper mutation, facilitates the binding of FMP-201300 to an allosteric pocket adjacent to the ATP-binding site. FMP-201300 therefore serves as a valuable springboard for the further development of compounds that can selectively target the three mammalian IP6Ks; either as analog-sensitive kinase inhibitors or as an allosteric lead compound for the WT kinases.
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Affiliation(s)
- Tim Aguirre
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
- Institut für Chemie, Humboldt-Universität zu BerlinBerlinGermany
| | - Gillian L Dornan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | | | - Carola Seyffarth
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Anja Schütz
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
| | | | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
- Institut für Chemie, Humboldt-Universität zu BerlinBerlinGermany
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8
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Heitmann T, Barrow JC. The Role of Inositol Hexakisphosphate Kinase in the Central Nervous System. Biomolecules 2023; 13:1317. [PMID: 37759717 PMCID: PMC10526494 DOI: 10.3390/biom13091317] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/23/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023] Open
Abstract
Inositol is a unique biological small molecule that can be phosphorylated or even further pyrophosphorylated on each of its six hydroxyl groups. These numerous phosphorylation states of inositol along with the kinases and phosphatases that interconvert them comprise the inositol phosphate signaling pathway. Inositol hexakisphosphate kinases, or IP6Ks, convert the fully mono-phosphorylated inositol to the pyrophosphate 5-IP7 (also denoted IP7). There are three isoforms of IP6K: IP6K1, 2, and 3. Decades of work have established a central role for IP6Ks in cell signaling. Genetic and pharmacologic manipulation of IP6Ks in vivo and in vitro has shown their importance in metabolic disease, chronic kidney disease, insulin signaling, phosphate homeostasis, and numerous other cellular and physiologic processes. In addition to these peripheral processes, a growing body of literature has shown the role of IP6Ks in the central nervous system (CNS). IP6Ks have a key role in synaptic vesicle regulation, Akt/GSK3 signaling, neuronal migration, cell death, autophagy, nuclear translocation, and phosphate homeostasis. IP6Ks' regulation of these cellular processes has functional implications in vivo in behavior and CNS anatomy.
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Affiliation(s)
- Tyler Heitmann
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, 725 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
- The Lieber Institute for Brain Development, 855 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
| | - James C. Barrow
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, 725 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
- The Lieber Institute for Brain Development, 855 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
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9
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Boregowda SV, Nanjappa MK, Booker CN, Strivelli J, Supper VM, Cooke PS, Phinney DG. Pharmacological Inhibition of Inositol Hexakisphosphate Kinase 1 Protects Mice against Obesity-Induced Bone Loss. BIOLOGY 2022; 11:biology11091257. [PMID: 36138736 PMCID: PMC9495776 DOI: 10.3390/biology11091257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/16/2022]
Abstract
Obesity and type II diabetes mellitus (T2DM) are prominent risk factors for secondary osteoporosis due to the negative impacts of hyperglycemia and excessive body fat on bone metabolism. While the armamentarium of anti-diabetic drugs is expanding, their negative or unknown impacts on bone metabolism limits effectiveness. The inactivation of inositol hexakisphosphate kinase 1 (IP6K1) protects mice from high-fat-diet (HFD)-induced obesity (DIO) and insulin resistance by enhancing thermogenic energy expenditure, but the role of this kinase and the consequences of its inhibition on bone metabolism are unknown. To determine if IP6K1 inhibition in obese mice affords protection against obesity-induced metabolic derangements and bone loss, we maintained 2-month-old mice on a normal chow control diet or HFD under thermal neutral conditions for 100 d. Beginning on day 40, HFD-fed mice were divided into two groups and administered daily injections of vehicle or the pan-IP6K inhibitor TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl) purine]. HFD-fed mice developed obesity, hyperglycemia, hyperlipidemia, and secondary osteoporosis, while TNP administration protected mice against HFD-induced metabolic and lipid derangements and preserved bone mass, mineral density, and trabecular microarchitecture, which correlated with reduced serum leptin levels, reduced marrow adiposity, and preservation of marrow resident skeletal stem/progenitor cells (SSPCs). TNP also exhibited hypotensive activity, an unrealized benefit of the drug, and its prolonged administration had no adverse impacts on spermatogenesis. Together, these data indicate that the inhibition of IP6K1 using selective inhibitors, such as TNP, may provide an effective strategy to manage obesity and T2DM due to its bone sparing effects.
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Affiliation(s)
- Siddaraju V. Boregowda
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL 33458, USA
| | | | - Cori N. Booker
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL 33458, USA
| | - Jacqueline Strivelli
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL 33458, USA
| | - Valentina M. Supper
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32610, USA
| | - Paul S. Cooke
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - Donald G. Phinney
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL 33458, USA
- Correspondence:
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10
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Li H, Datunashvili M, Reyes RC, Voglmaier SM. Inositol hexakisphosphate kinases differentially regulate trafficking of vesicular glutamate transporters 1 and 2. Front Cell Neurosci 2022; 16:926794. [PMID: 35936490 PMCID: PMC9355605 DOI: 10.3389/fncel.2022.926794] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/27/2022] [Indexed: 11/16/2022] Open
Abstract
Inositol pyrophosphates have been implicated in cellular signaling and membrane trafficking, including synaptic vesicle (SV) recycling. Inositol hexakisphosphate kinases (IP6Ks) and their product, diphosphoinositol pentakisphosphate (PP-IP5 or IP7), directly and indirectly regulate proteins important in vesicle recycling by the activity-dependent bulk endocytosis pathway (ADBE). In the present study, we show that two isoforms, IP6K1 and IP6K3, are expressed in axons. The role of the kinases in SV recycling are investigated using pharmacologic inhibition, shRNA knockdown, and IP6K1 and IP6K3 knockout mice. Live-cell imaging experiments use optical reporters of SV recycling based on vesicular glutamate transporter isoforms, VGLUT1- and VGLUT2-pHluorins (pH), which recycle differently. VGLUT1-pH recycles by classical AP-2 dependent endocytosis under moderate stimulation conditions, while VGLUT2-pH recycles using AP-1 and AP-3 adaptor proteins as well. Using a short stimulus to release the readily releasable pool (RRP), we show that IP6K1 KO increases exocytosis of both VGLUT1-and VGLUT2-pH, while IP6K3 KO decreases the amount of both transporters in the RRP. In electrophysiological experiments we measure glutamate signaling with short stimuli and under the intense stimulation conditions that trigger bulk endocytosis. IP6K1 KO increases synaptic facilitation and IP6K3 KO decreases facilitation compared to wild type in CA1 hippocampal Schaffer collateral synapses. After intense stimulation, the rate of endocytosis of VGLUT2-pH, but not VGLUT1-pH, is increased by knockout, knockdown, and pharmacologic inhibition of IP6Ks. Thus IP6Ks differentially affect the endocytosis of two SV protein cargos that use different endocytic pathways. However, while IP6K1 KO and IP6K3 KO exert similar effects on endocytosis after stimulation, the isoforms exert different effects on exocytosis earlier in the stimulus and on the early phase of glutamate release. Taken together, the data indicate a role for IP6Ks both in exocytosis early in the stimulation period and in endocytosis, particularly under conditions that may utilize AP-1/3 adaptors.
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11
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Ceyhan Y, Zhang M, Sandoval CG, Agoulnik AI, Agoulnik IU. Expression pattern and the roles of phosphatidylinositol phosphatases in testis. Biol Reprod 2022; 107:902-915. [PMID: 35766372 DOI: 10.1093/biolre/ioac132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/02/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Phosphoinositides (PIs) are relatively rare lipid components of the cellular membranes. Their homeostasis is tightly controlled by specific PI kinases and phosphatases. PIs play essential roles in cellular signaling, cytoskeletal organization, and secretory processes in various diseases and normal physiology. Gene targeting experiments strongly suggest that in mice with deficiency of several PI phosphatases such as Pten, Mtmrs, Inpp4b, and Inpp5b, spermatogenesis is affected, resulting in partial or complete infertility. Similarly, in men, loss of several of the PIP phosphatases is observed in infertility characterized by the lack of mature sperm. Using available gene expression databases, we compare expression of known PI phosphatases in various testicular cell types, infertility patients, and mouse age-dependent testicular gene expression, and discuss their potential roles in testis physiology and spermatogenesis.
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Affiliation(s)
- Yasemin Ceyhan
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Manqi Zhang
- Department of Medicine, Duke University, Durham, NC, USA
| | - Carlos G Sandoval
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,New York University Grossman School of Medicine, New York, NY, USA
| | - Alexander I Agoulnik
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Irina U Agoulnik
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
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12
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Tu-Sekine B, Kim SF. The Inositol Phosphate System-A Coordinator of Metabolic Adaptability. Int J Mol Sci 2022; 23:6747. [PMID: 35743190 PMCID: PMC9223660 DOI: 10.3390/ijms23126747] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
All cells rely on nutrients to supply energy and carbon building blocks to support cellular processes. Over time, eukaryotes have developed increasingly complex systems to integrate information about available nutrients with the internal state of energy stores to activate the necessary processes to meet the immediate and ongoing needs of the cell. One such system is the network of soluble and membrane-associated inositol phosphates that coordinate the cellular responses to nutrient uptake and utilization from growth factor signaling to energy homeostasis. In this review, we discuss the coordinated interactions of the inositol polyphosphates, inositol pyrophosphates, and phosphoinositides in major metabolic signaling pathways to illustrate the central importance of the inositol phosphate signaling network in nutrient responses.
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Affiliation(s)
- Becky Tu-Sekine
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University, Baltimore, MD 21224, USA;
| | - Sangwon F. Kim
- Department of Medicine and Neuroscience, Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
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13
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Whole Body Ip6k1 Deletion Protects Mice from Age-Induced Weight Gain, Insulin Resistance and Metabolic Dysfunction. Int J Mol Sci 2022; 23:ijms23042059. [PMID: 35216174 PMCID: PMC8878859 DOI: 10.3390/ijms23042059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/05/2022] [Accepted: 02/10/2022] [Indexed: 12/21/2022] Open
Abstract
(1) Background: We previously demonstrated that disruption of IP6K1 improves metabolism, protecting mice from high-fat diet-induced obesity, insulin resistance, and non-alcoholic fatty liver disease and steatohepatitis. Age-induced metabolic dysfunction is a major risk factor for metabolic diseases. The involvement of IP6K1 in this process is unknown. (2) Methods: Here, we compared body and fat mass, insulin sensitivity, energy expenditure and serum-, adipose tissue- and liver-metabolic parameters of chow-fed, aged, wild type (aWT) and whole body Ip6k1 knockout (aKO) mice. (3) Results: IP6K1 was upregulated in the adipose tissue and liver of aWT mice compared to young WT mice. Moreover, Ip6k1 deletion blocked age-induced increase in body- and fat-weight and insulin resistance in mice. aKO mice oxidized carbohydrates more efficiently. The knockouts displayed reduced levels of serum insulin, triglycerides, and non-esterified fatty acids. Ip6k1 deletion partly protected age-induced decline of the thermogenic uncoupling protein UCP1 in inguinal white adipose tissue. Targets inhibited by IP6K1 activity such as the insulin sensitivity- and energy expenditure-inducing protein kinases, protein kinase B (PKB/Akt) and AMP-activated protein kinase (AMPK), were activated in the adipose tissue and liver of aKO mice. (4) Conclusions: Ip6k1 deletion maintains healthy metabolism in aging and thus, targeting this kinase may delay the development of age-induced metabolic dysfunction.
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14
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Lee H, Park SJ, Hong S, Lim SW, Kim S. Deletion of IP6K1 in mice accelerates tumor growth by dysregulating the tumor-immune microenvironment. Anim Cells Syst (Seoul) 2022; 26:19-27. [PMID: 35308129 PMCID: PMC8928833 DOI: 10.1080/19768354.2022.2029560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A family of inositol hexakisphosphate kinases (IP6Ks) catalyzes the production of inositol pyrophosphate IP7 (5-diphosphoinositolpentakisphosphate) which is known to modulate various biological events such as cell growth. While targeting IP6K1 in various cancer cells has been well reported to control cancer cell motility and invasiveness, the role of host IP6K1 in tumor progression remains unknown. By using a syngeneic MC38 murine mouse colon carcinoma model, here we examined how host IP6K1 in the tumor microenvironment influences tumor growth. In IP6K1 knockout (KO) mice, the growth of MC38 tumor cells was markedly accelerated and host survival was significantly shortened compared with wild-type (WT). Our flow cytometric analysis revealed that tumors grown in IP6K1 KO mice had lower immune suppressive myeloid cells and M1 polarized macrophages. Notably, infiltration of both antigen-presenting dendritic cells and CD8+ cytotoxic T lymphocytes into the tumor tissues was remarkably abrogated in IP6K1 KO condition. These studies suggest that enhanced tumor growth in IP6K1 KO mice resulted from reduced anti-tumor immunity due to disturbed immune cell actions in the tumor microenvironment. In conclusion, we demonstrate that host IP6K1 acts as a tumor suppressor, most likely by fine-tuning diverse tumor-immune cell interactions, which might have implications for improving the host response against cancer progression.
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Affiliation(s)
- Haein Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seung Ju Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Sehoon Hong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seol-Wa Lim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seyun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- KAIST Institute for the BioCentury, KAIST, Daejeon, Republic of Korea
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15
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Shah A, Bhandari R. IP6K1 upregulates the formation of processing bodies by influencing protein-protein interactions on the mRNA cap. J Cell Sci 2021; 134:273758. [PMID: 34841428 DOI: 10.1242/jcs.259117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 11/11/2021] [Indexed: 11/20/2022] Open
Abstract
Inositol hexakisphosphate kinase 1 (IP6K1) is a small molecule kinase that catalyzes the conversion of the inositol phosphate IP6 to 5-IP7. We show that IP6K1 acts independently of its catalytic activity to upregulate the formation of processing bodies (P-bodies), which are cytoplasmic ribonucleoprotein granules that store translationally repressed mRNA. IP6K1 does not localise to P-bodies, but instead binds to ribosomes, where it interacts with the mRNA decapping complex - the scaffold protein EDC4, activator proteins DCP1A/B, decapping enzyme DCP2 and RNA helicase DDX6. Along with its partner 4E-T, DDX6 is known to nucleate protein-protein interactions on the 5' mRNA cap to facilitate P-body formation. IP6K1 binds the translation initiation complex eIF4F on the mRNA cap, augmenting the interaction of DDX6 with 4E-T (also known as EIF4ENIF1) and the cap-binding protein eIF4E. Cells with reduced IP6K1 show downregulated microRNA-mediated translational suppression and increased stability of DCP2-regulated transcripts. Our findings unveil IP6K1 as a novel facilitator of proteome remodelling on the mRNA cap, tipping the balance in favour of translational repression over initiation, thus leading to P-body assembly. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Akruti Shah
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India.,Graduate Studies, Manipal Academy of Higher Education, Manipal 576104, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad 500039, India
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16
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Mukherjee S, Chakraborty M, Ulmasov B, McCommis K, Zhang J, Carpenter D, Msengi EN, Haubner J, Guo C, Pike DP, Ghoshal S, Ford DA, Neuschwander-Tetri BA, Chakraborty A. Pleiotropic actions of IP6K1 mediate hepatic metabolic dysfunction to promote nonalcoholic fatty liver disease and steatohepatitis. Mol Metab 2021; 54:101364. [PMID: 34757046 PMCID: PMC8609165 DOI: 10.1016/j.molmet.2021.101364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/11/2021] [Accepted: 10/23/2021] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Obesity and insulin resistance greatly increase the risk of nonalcoholic fatty liver disease and steatohepatitis (NAFLD/NASH). We have previously discovered that whole-body and adipocyte-specific Ip6k1deletion protects mice from high-fat-diet-induced obesity and insulin resistance due to improved adipocyte thermogenesis and insulin signaling. Here, we aimed to determine the impact of hepatocyte-specific and whole-body Ip6k1 deletion (HKO and Ip6k1-KO or KO) on liver metabolism and NAFLD/NASH. METHODS Body weight and composition; energy expenditure; glycemic profiles; and serum and liver metabolic, inflammatory, fibrotic and toxicity parameters were assessed in mice fed Western and high-fructose diet (HFrD) (WD: 40% kcal fat, 1.25% cholesterol, no added choline and HFrD: 60% kcal fructose). Mitochondrial oxidative capacity was evaluated in isolated hepatocytes. RNA-Seq was performed in liver samples. Livers from human NASH patients were analyzed by immunoblotting and mass spectrometry. RESULTS HKO mice displayed increased hepatocyte mitochondrial oxidative capacity and improved insulin sensitivity but were not resistant to body weight gain. Improved hepatocyte metabolism partially protected HKO mice from NAFLD/NASH. In contrast, enhanced whole-body metabolism and reduced body fat accumulation significantly protected whole-body Ip6k1-KO mice from NAFLD/NASH. Mitochondrial oxidative pathways were upregulated, whereas gluconeogenic and fibrogenic pathways were downregulated in Ip6k1-KO livers. Furthermore, IP6K1 was upregulated in human NASH livers and interacted with the enzyme O-GlcNAcase that reduces protein O-GlcNAcylation. Protein O-GlcNAcylation was found to be reduced in Ip6k1-KO and HKO mouse livers. CONCLUSION Pleiotropic actions of IP6K1 in the liver and other metabolic tissues mediate hepatic metabolic dysfunction and NAFLD/NASH, and thus IP6K1 deletion may be a potential treatment target for this disease.
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Affiliation(s)
- Sandip Mukherjee
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Molee Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Barbara Ulmasov
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Kyle McCommis
- Department of Biochemistry, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Jinsong Zhang
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Danielle Carpenter
- Department of Pathology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Eliwaza Naomi Msengi
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Jake Haubner
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Chun Guo
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Daniel P Pike
- Department of Biochemistry, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Sarbani Ghoshal
- Department of Biological Sc. and Geology, QCC-CUNY, Bayside, NY, USA
| | - David A Ford
- Department of Biochemistry, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Brent A Neuschwander-Tetri
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Anutosh Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA.
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17
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Kröber T, Bartsch SM, Fiedler D. Pharmacological tools to investigate inositol polyphosphate kinases - Enzymes of increasing therapeutic relevance. Adv Biol Regul 2021; 83:100836. [PMID: 34802993 DOI: 10.1016/j.jbior.2021.100836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/01/2023]
Abstract
Inositol poly- and pyrophosphates (InsPs and PP-InsPs) are a group of central eukaryotic metabolites and signaling molecules. Due to the diverse cellular functions and widespread diseases InsPs and PP-InsPs are associated with, pharmacological targeting of the kinases involved in their biosynthesis has become a significant research interest in the last decade. In particular, the development of inhibitors for inositol hexakisphosphate kinases (IP6Ks) has leaped forward, while other inositol phosphate kinases have received scant attention. This review summarizes the efforts undertaken so far for discovering potent and selective inhibitors for this diverse group of small molecule kinases. The benefits of pharmacological inhibition are highlighted, given the multiple kinase-independent functions of inositol phosphate kinases. The distinct structural families of InsP and PP-InsP kinases are presented, and we discuss how compound availability for different inositol phosphate kinase families varies drastically. Lead compound discovery and optimization for the inositol kinases would benefit from detailed structural information on the ATP-binding sites of these kinases, as well as reliable biochemical and cellular read-outs to monitor inositol phosphate kinase activity in complex settings. Efforts to further tune well-established inhibitors, while simultaneously reviving tool compound development for the more neglected kinases from this family are indisputably worthwhile, considering the large potential therapeutic benefits.
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Affiliation(s)
- Tim Kröber
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125, Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
| | - Simon M Bartsch
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125, Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
| | - Dorothea Fiedler
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125, Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
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18
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Coupled protein synthesis and ribosome-guided piRNA processing on mRNAs. Nat Commun 2021; 12:5970. [PMID: 34645830 PMCID: PMC8514520 DOI: 10.1038/s41467-021-26233-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/17/2021] [Indexed: 12/16/2022] Open
Abstract
PIWI-interacting small RNAs (piRNAs) protect the germline genome and are essential for fertility. piRNAs originate from transposable element (TE) RNAs, long non-coding RNAs, or 3´ untranslated regions (3´UTRs) of protein-coding messenger genes, with the last being the least characterized of the three piRNA classes. Here, we demonstrate that the precursors of 3´UTR piRNAs are full-length mRNAs and that post-termination 80S ribosomes guide piRNA production on 3´UTRs in mice and chickens. At the pachytene stage, when other co-translational RNA surveillance pathways are sequestered, piRNA biogenesis degrades mRNAs right after pioneer rounds of translation and fine-tunes protein production from mRNAs. Although 3´UTR piRNA precursor mRNAs code for distinct proteins in mice and chickens, they all harbor embedded TEs and produce piRNAs that cleave TEs. Altogether, we discover a function of the piRNA pathway in fine-tuning protein production and reveal a conserved piRNA biogenesis mechanism that recognizes translating RNAs in amniotes.
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19
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Zhang X, Li N, Zhang J, Zhang Y, Yang X, Luo Y, Zhang B, Xu Z, Zhu Z, Yang X, Yan Y, Lin B, Wang S, Chen D, Ye C, Ding Y, Lou M, Wu Q, Hou Z, Zhang K, Liang Z, Wei A, Wang B, Wang C, Jiang N, Zhang W, Xiao G, Ma C, Ren Y, Qi X, Han W, Wang C, Rao F. 5-IP 7 is a GPCR messenger mediating neural control of synaptotagmin-dependent insulin exocytosis and glucose homeostasis. Nat Metab 2021; 3:1400-1414. [PMID: 34663975 DOI: 10.1038/s42255-021-00468-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 09/02/2021] [Indexed: 11/08/2022]
Abstract
5-diphosphoinositol pentakisphosphate (5-IP7) is a signalling metabolite linked to various cellular processes. How extracellular stimuli elicit 5-IP7 signalling remains unclear. Here we show that 5-IP7 in β cells mediates parasympathetic stimulation of synaptotagmin-7 (Syt7)-dependent insulin release. Mechanistically, vagal stimulation and activation of muscarinic acetylcholine receptors triggers Gαq-PLC-PKC-PKD-dependent signalling and activates IP6K1, the 5-IP7 synthase. Whereas both 5-IP7 and its precursor IP6 compete with PIP2 for binding to Syt7, Ca2+ selectively binds 5-IP7 with high affinity, freeing Syt7 to enable fusion of insulin-containing vesicles with the cell membrane. β-cell-specific IP6K1 deletion diminishes insulin secretion and glucose clearance elicited by muscarinic stimulation, whereas mice carrying a phosphorylation-mimicking, hyperactive IP6K1 mutant display augmented insulin release, congenital hyperinsulinaemia and obesity. These phenotypes are absent in mice lacking Syt7. Our study proposes a new conceptual framework for inositol pyrophosphate physiology in which 5-IP7 acts as a GPCR second messenger at the interface between peripheral nervous system and metabolic organs, transmitting Gq-coupled GPCR stimulation to unclamp Syt7-dependent, and perhaps other, exocytotic events.
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Affiliation(s)
- Xiaozhe Zhang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Na Li
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Jun Zhang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yanshen Zhang
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- Department of Neurology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Xiaoli Yang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yifan Luo
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Bobo Zhang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Zhixue Xu
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Zhenhua Zhu
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Xiuyan Yang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yuan Yan
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Biao Lin
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Shen Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Da Chen
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- Department of Neurology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Caichao Ye
- Department of Physics and Shenzhen Institute for Quantum Science & Technology, Southern University of Science and Technology, Shenzhen, China
| | - Yan Ding
- National Institute of Biological Sciences, Beijing, China
| | - Mingliang Lou
- National Institute of Biological Sciences, Beijing, China
| | - Qingcui Wu
- National Institute of Biological Sciences, Beijing, China
| | - Zhanfeng Hou
- National Institute of Biological Sciences, Beijing, China
| | - Keren Zhang
- BGI-Shenzhen, Beishan Industrial Zone 11th building, Shenzhen, China
| | - Ziming Liang
- Department of Hepatic Surgery, the Third People's Hospital of Shenzhen and the Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Anqi Wei
- Neuroscience Research Center, Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Bianbian Wang
- Neuroscience Research Center, Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Changhe Wang
- Neuroscience Research Center, Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Nan Jiang
- Department of Hepatic Surgery, the Third People's Hospital of Shenzhen and the Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Wenqing Zhang
- Department of Physics and Shenzhen Institute for Quantum Science & Technology, Southern University of Science and Technology, Shenzhen, China
| | - Guozhi Xiao
- Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Ren
- BGI-Shenzhen, Beishan Industrial Zone 11th building, Shenzhen, China
| | - Xiangbing Qi
- National Institute of Biological Sciences, Beijing, China
| | - Weiping Han
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research, Singapore, Singapore
- Center for Neuro-Metabolism and Regeneration Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Chao Wang
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
- Department of Neurology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
| | - Feng Rao
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
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20
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Couto D, Richter A, Walter H, Furkert D, Hothorn M, Fiedler D. Using Biotinylated myo-Inositol Hexakisphosphate to Investigate Inositol Pyrophosphate-Protein Interactions with Surface-Based Biosensors. Biochemistry 2021; 60:2739-2748. [PMID: 34499474 DOI: 10.1021/acs.biochem.1c00497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Inositol pyrophosphates (PP-InsPs) are highly phosphorylated molecules that have emerged as central nutrient messengers in eukaryotic organisms. They can bind to structurally diverse target proteins to regulate biological functions, such as protein-protein interactions. PP-InsPs are strongly negatively charged and interact with highly basic surface patches in proteins, making their quantitative biochemical analysis challenging. Here, we present the synthesis of biotinylated myo-inositol hexakisphosphates and their application in surface plasmon resonance and grating-coupled interferometry assays, to enable the rapid identification, validation, and kinetic characterization of InsP- and PP-InsP-protein interactions.
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Affiliation(s)
- Daniel Couto
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Annika Richter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Henriette Walter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - David Furkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Michael Hothorn
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
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21
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Hostachy S, Utesch T, Franke K, Dornan GL, Furkert D, Türkaydin B, Haucke V, Sun H, Fiedler D. Dissecting the activation of insulin degrading enzyme by inositol pyrophosphates and their bisphosphonate analogs. Chem Sci 2021; 12:10696-10702. [PMID: 34476054 PMCID: PMC8372538 DOI: 10.1039/d1sc02975d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/06/2021] [Indexed: 11/21/2022] Open
Abstract
Inositol poly- and pyrophosphates (InsPs and PP-InsPs) are densely phosphorylated eukaryotic messengers, which are involved in numerous cellular processes. To elucidate their signaling functions at the molecular level, non-hydrolyzable bisphosphonate analogs of inositol pyrophosphates, PCP-InsPs, have been instrumental. Here, an efficient synthetic strategy to obtain these analogs in unprecedented quantities is described - relying on the use of combined phosphate ester-phosphoramidite reagents. The PCP-analogs, alongside their natural counterparts, were applied to investigate their regulatory effect on insulin-degrading enzyme (IDE), using a range of biochemical, biophysical and computational methods. A unique interplay between IDE, its substrates and the PP-InsPs was uncovered, in which the PP-InsPs differentially modulated the activity of the enzyme towards short peptide substrates. Aided by molecular docking and molecular dynamics simulations, a flexible binding mode for the InsPs/PP-InsPs was identified at the anion binding site of IDE. Targeting IDE for therapeutic purposes should thus take regulation by endogenous PP-InsP metabolites into account.
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Affiliation(s)
- Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - Tillmann Utesch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - Katy Franke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - Gillian Leigh Dornan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - David Furkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
- Institut für Chemie, Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Berke Türkaydin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - Han Sun
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Robert-Rössle Str. 10 13125 Berlin Germany
- Institut für Chemie, Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
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Inositol pyrophosphates promote MYC polyubiquitination by FBW7 to regulate cell survival. Biochem J 2021; 478:1647-1661. [PMID: 33821962 DOI: 10.1042/bcj20210081] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/26/2021] [Accepted: 04/06/2021] [Indexed: 12/21/2022]
Abstract
The transcription factor MYC regulates cell survival and growth, and its level is tightly controlled in normal cells. We report that serine pyrophosphorylation - a posttranslational modification triggered by inositol pyrophosphate signaling molecules - controls MYC levels via regulated protein degradation. We find that endogenous MYC is stabilized and less polyubiquitinated in cells with reduced inositol pyrophosphates. We show that the inositol pyrophosphate 5-IP7 transfers its high-energy beta phosphate moiety to pre-phosphorylated serine residues in the central PEST domain of MYC. Loss of serine pyrophosphorylation in the PEST domain lowers the extent of MYC polyubiquitination and increases its stability. Fusion to the MYC PEST domain lowers the stability of GFP, but this effect is dependent on the extent of PEST domain pyrophosphorylation. The E3 ubiquitin ligase FBW7 can bind directly to the PEST domain of MYC, and this interaction is exclusively dependent on serine pyrophosphorylation. A stabilized, pyrophosphorylation-deficient form of MYC increases cell death during growth stress in untransformed cells. Splenocytes from mice lacking IP6K1, a kinase responsible for the synthesis of 5-IP7, have higher levels of MYC, and show increased cell proliferation in response to mitogens, compared with splenocytes from wild type mice. Thus, control of MYC stability through a novel pyro-phosphodegron provides unexpected insight into the regulation of cell survival in response to environmental cues.
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23
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Li K, Xu J, Luo Y, Zou D, Han R, Zhong S, Zhao Q, Mang X, Li M, Si Y, Lu Y, Li P, Jin C, Wang Z, Wang F, Miao S, Wen B, Wang L, Ma Y, Yu J, Song W. Panoramic transcriptome analysis and functional screening of long noncoding RNAs in mouse spermatogenesis. Genome Res 2020; 31:13-26. [PMID: 33328167 PMCID: PMC7849387 DOI: 10.1101/gr.264333.120] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022]
Abstract
Long noncoding RNAs (lncRNAs) have emerged as diverse functional regulators involved in mammalian development; however, large-scale functional investigation of lncRNAs in mammalian spermatogenesis in vivo is lacking. Here, we delineated the global lncRNA expression landscape in mouse spermatogenesis and identified 968 germ cell signature lncRNAs. By combining bioinformatics and functional screening, we identified three functional lncRNAs (Gm4665, 1700027A15Rik, and 1700052I22Rik) that directly influence spermatogenesis in vivo. Knocking down Gm4665 hampered the development of round spermatids into elongating spermatids and disrupted key spermatogenic gene expression. Mechanistically, lncRNA Gm4665 localized in the nucleus of round spermatids and occupied the genomic regulatory region of important spermatogenic genes including Ip6k1 and Akap3. These findings provide a valuable resource and framework for future functional analysis of lncRNAs in spermatogenesis and their potential roles in other biological processes.
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Affiliation(s)
- Kai Li
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Jiayue Xu
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Yanyun Luo
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Dingfeng Zou
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Ruiqin Han
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Shunshun Zhong
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Qing Zhao
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Xinyu Mang
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Mengzhen Li
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Yanmin Si
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Yan Lu
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Pengyu Li
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Cheng Jin
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Zhipeng Wang
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Fang Wang
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Shiying Miao
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Bo Wen
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Linfang Wang
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Yanni Ma
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Jia Yu
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Wei Song
- Department of Biochemistry and Molecular Biology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
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Role of Inositols and Inositol Phosphates in Energy Metabolism. Molecules 2020; 25:molecules25215079. [PMID: 33139672 PMCID: PMC7663797 DOI: 10.3390/molecules25215079] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/27/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022] Open
Abstract
Recently, inositols, especially myo-inositol and inositol hexakisphosphate, also known as phytic acid or IP6, with their biological activities received much attention for their role in multiple health beneficial effects. Although their roles in cancer treatment and prevention have been extensively reported, interestingly, they may also have distinctive properties in energy metabolism and metabolic disorders. We review inositols and inositol phosphate metabolism in mammalian cells to establish their biological activities and highlight their potential roles in energy metabolism. These molecules are known to decrease insulin resistance, increase insulin sensitivity, and have diverse properties with importance from cell signaling to metabolism. Evidence showed that inositol phosphates might enhance the browning of white adipocytes and directly improve insulin sensitivity through adipocytes. In addition, inositol pyrophosphates containing high-energy phosphate bonds are considered in increasing cellular energetics. Despite all recent advances, many aspects of the bioactivity of inositol phosphates are still not clear, especially their effects on insulin resistance and alteration of metabolism, so more research is needed.
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25
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Minini M, Senni A, Unfer V, Bizzarri M. The Key Role of IP 6K: A Novel Target for Anticancer Treatments? Molecules 2020; 25:molecules25194401. [PMID: 32992691 PMCID: PMC7583815 DOI: 10.3390/molecules25194401] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/29/2022] Open
Abstract
Inositol and its phosphate metabolites play a pivotal role in several biochemical pathways and gene expression regulation: inositol pyrophosphates (PP-IPs) have been increasingly appreciated as key signaling modulators. Fluctuations in their intracellular levels hugely impact the transfer of phosphates and the phosphorylation status of several target proteins. Pharmacological modulation of the proteins associated with PP-IP activities has proved to be beneficial in various pathological settings. IP7 has been extensively studied and found to play a key role in pathways associated with PP-IP activities. Three inositol hexakisphosphate kinase (IP6K) isoforms regulate IP7 synthesis in mammals. Genomic deletion or enzymic inhibition of IP6K1 has been shown to reduce cell invasiveness and migration capacity, protecting against chemical-induced carcinogenesis. IP6K1 could therefore be a useful target in anticancer treatment. Here, we summarize the current understanding that established IP6K1 and the other IP6K isoforms as possible targets for cancer therapy. However, it will be necessary to determine whether pharmacological inhibition of IP6K is safe enough to begin clinical study. The development of safe and selective inhibitors of IP6K isoforms is required to minimize undesirable effects.
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Affiliation(s)
- Mirko Minini
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
- Department of Surgery ‘P. Valdoni’, Sapienza University of Rome, 00161 Rome, Italy
- Systems Biology Group Lab, Sapienza University of Rome, 00185 Rome, Italy;
- Correspondence: (M.M.); (M.B.)
| | - Alice Senni
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
- Department of Surgery ‘P. Valdoni’, Sapienza University of Rome, 00161 Rome, Italy
| | - Vittorio Unfer
- Systems Biology Group Lab, Sapienza University of Rome, 00185 Rome, Italy;
| | - Mariano Bizzarri
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
- Systems Biology Group Lab, Sapienza University of Rome, 00185 Rome, Italy;
- Correspondence: (M.M.); (M.B.)
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26
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Furkert D, Hostachy S, Nadler-Holly M, Fiedler D. Triplexed Affinity Reagents to Sample the Mammalian Inositol Pyrophosphate Interactome. Cell Chem Biol 2020; 27:1097-1108.e4. [PMID: 32783964 DOI: 10.1016/j.chembiol.2020.07.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/19/2020] [Accepted: 07/22/2020] [Indexed: 11/15/2022]
Abstract
The inositol pyrophosphates (PP-InsPs) are a ubiquitous group of highly phosphorylated eukaryotic messengers. They have been linked to a panoply of central cellular processes, but a detailed understanding of the discrete signaling events is lacking in most cases. To create a more mechanistic picture of PP-InsP signaling, we sought to annotate the mammalian interactome of the most abundant inositol pyrophosphate 5PP-InsP5. To do so, triplexed affinity reagents were developed, in which a metabolically stable PP-InsP analog was immobilized in three different ways. Application of these triplexed reagents to mammalian lysates identified between 300 and 400 putative interacting proteins. These interactomes revealed connections between 5PP-InsP5 and central cellular regulators, such as lipid phosphatases, protein kinases, and GTPases, and identified protein domains commonly targeted by 5PP-InsP5. Both the triplexed affinity reagents, and the proteomic datasets, constitute powerful resources for the community, to launch future investigations into the multiple signaling modalities of inositol pyrophosphates.
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Affiliation(s)
- David Furkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany; Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Michal Nadler-Holly
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany; Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
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27
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Mukherjee S, Haubner J, Chakraborty A. Targeting the Inositol Pyrophosphate Biosynthetic Enzymes in Metabolic Diseases. Molecules 2020; 25:molecules25061403. [PMID: 32204420 PMCID: PMC7144392 DOI: 10.3390/molecules25061403] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 12/12/2022] Open
Abstract
In mammals, a family of three inositol hexakisphosphate kinases (IP6Ks) synthesizes the inositol pyrophosphate 5-IP7 from IP6. Genetic deletion of Ip6k1 protects mice from high fat diet induced obesity, insulin resistance and fatty liver. IP6K1 generated 5-IP7 promotes insulin secretion from pancreatic β-cells, whereas it reduces insulin signaling in metabolic tissues by inhibiting the protein kinase Akt. Thus, IP6K1 promotes high fat diet induced hyperinsulinemia and insulin resistance in mice while its deletion has the opposite effects. IP6K1 also promotes fat accumulation in the adipose tissue by inhibiting the protein kinase AMPK mediated energy expenditure. Genetic deletion of Ip6k3 protects mice from age induced fat accumulation and insulin resistance. Accordingly, the pan IP6K inhibitor TNP [N2-(m-trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates obesity, insulin resistance and fatty liver in diet induced obese mice by improving Akt and AMPK mediated insulin sensitivity and energy expenditure. TNP also protects mice from bone loss, myocardial infarction and ischemia reperfusion injury. Thus, the IP6K pathway is a potential target in obesity and other metabolic diseases. Here, we summarize the studies that established IP6Ks as a potential target in metabolic diseases. Further studies will reveal whether inhibition of this pathway has similar pleiotropic benefits on metabolic health of humans.
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28
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Barclay RD, Beals JW, Drnevich J, Imai BS, Yau PM, Ulanov AV, Tillin NA, Villegas-Montes M, Paluska SA, Watt PW, De Lisio M, Burd NA, Mackenzie RW. Ingestion of lean meat elevates muscle inositol hexakisphosphate kinase 1 protein content independent of a distinct post-prandial circulating proteome in young adults with obesity. Metabolism 2020; 102:153996. [PMID: 31678069 PMCID: PMC7268923 DOI: 10.1016/j.metabol.2019.153996] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/25/2019] [Accepted: 10/06/2019] [Indexed: 01/05/2023]
Abstract
BACKGROUND We have recently shown that a novel signalling kinase, inositol hexakisphosphate kinase 1 (IP6K1), is implicated in whole-body insulin resistance via its inhibitory action on Akt. Insulin and insulin like growth factor 1 (IGF-1) share many intracellular processes with both known to play a key role in glucose and protein metabolism in skeletal muscle. AIMS We aimed to compare IGF/IP6K1/Akt signalling and the plasma proteomic signature in individuals with a range of BMIs after ingestion of lean meat. METHODS Ten lean [Body mass index (BMI) (in kg/m2): 22.7 ± 0.4; Homeostatic model assessment of insulin resistance (HOMAIR): 1.36 ± 0.17], 10 overweight (BMI: 27.1 ± 0.5; HOMAIR: 1.25 ± 0.11), and 10 obese (BMI: 35.9 ± 1.3; HOMAIR: 5.82 ± 0.81) adults received primed continuous L-[ring-13C6]phenylalanine infusions. Blood and muscle biopsy samples were collected at 0 min (post-absorptive), 120 min and 300 min relative to the ingestion of 170 g pork loin (36 g protein and 5 g fat) to examine skeletal muscle protein signalling, plasma proteomic signatures, and whole-body phenylalanine disappearance rates (Rd). RESULTS Phenylalanine Rd was not different in obese compared to lean individuals at all time points and was not responsive to a pork ingestion (basal, P = 0.056; 120 & 300 min, P > 0.05). IP6K1 was elevated in obese individuals at 120 min post-prandial vs basal (P < 0.05). There were no acute differences plasma proteomic profiles between groups in the post-prandial state (P > 0.05). CONCLUSIONS These data demonstrate, for the first time that muscle IP6K1 protein content is elevated after lean meat ingestion in obese adults, suggesting that IP6K1 may be contributing to the dysregulation of nutrient uptake in skeletal muscle. In addition, proteomic analysis showed no differences in proteomic signatures between obese, overweight or lean individuals.
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Affiliation(s)
- Richie D Barclay
- Department of Life Sciences, University of Roehampton, London, UK
| | - Joseph W Beals
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
| | - Jenny Drnevich
- High-Performance Biological Computing, Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL, United States
| | - Brian S Imai
- Protein Sciences Facility, Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL, United States
| | - Peter M Yau
- Metabolomics Facility, Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL, United States
| | - Alexander V Ulanov
- Department of Kinesiology and Community Health, University of Illinois, Urbana, IL, United States
| | - Neale A Tillin
- Department of Life Sciences, University of Roehampton, London, UK
| | | | - Scott A Paluska
- Department of Family Medicine, University of Illinois, Urbana, IL, United States
| | - Peter W Watt
- University of Brighton, Welkin Laboratories, Eastbourne, UK
| | - Michael De Lisio
- School of Human Kinetics, Brain and Mind Institute, Center on Neuromuscular Disease, Regenerative Medicine Program, University of Ottawa, Ottawa, ON, Canada
| | - Nicholas A Burd
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States; Department of Kinesiology and Community Health, University of Illinois, Urbana, IL, United States
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Chanduri M, Bhandari R. Back-Pyrophosphorylation Assay to Detect In Vivo InsP 7-Dependent Protein Pyrophosphorylation in Mammalian Cells. Methods Mol Biol 2020; 2091:93-105. [PMID: 31773573 DOI: 10.1007/978-1-0716-0167-9_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Protein pyrophosphorylation involves the transfer of a high-energy β-phosphate from inositol pyrophosphates, such as diphosphoinositol pentakisphosphate (InsP7) to phosphorylated serine residues. Over a decade of research has established several proteins, involved in diverse physiological processes, as substrates of InsP7-mediated pyrophosphorylation. However, the need for detection of this posttranslational modification on endogenous proteins is paramount. "Back-pyrophosphorylation" is a simple technique to test whether a native protein undergoes InsP7-mediated pyrophosphorylation inside cells. The basis of this technique relies on the fact that a target protein isolated from cells with lower InsP7 levels exists in a hypo-pyrophosphorylated form as compared to the same protein isolated from cells with normal InsP7 levels. Hence, when radiolabeled InsP7 is added to a target protein immunoprecipitated from both these cell types, the hypopyrophosphorylated protein accepts a higher amount of radiolabeled phosphate when compared to the protein isolated from wild-type cells. This chapter provides detailed methods to identify an InsP7 target protein and conduct a back-pyrophosphorylation assay on a target protein immunoprecipitated from cells with normal versus reduced InsP7 levels, to confirm its endogenous pyrophosphorylation status.
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Affiliation(s)
- Manasa Chanduri
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India.
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30
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Lu H, Cowieson AJ, Wilson JW, Ajuwon KM, Adeola O. Extra-phosphoric effects of super dosing phytase on growth performance of pigs is not solely due to release of myo-inositol. J Anim Sci 2019; 97:3898-3906. [PMID: 31284292 DOI: 10.1093/jas/skz232] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/06/2019] [Indexed: 12/20/2022] Open
Abstract
Two experiments were conducted to determine the effects of myo-inositol and phytase on growth performance, plasma metabolites, and nutrient digestibility of growing pigs. In experiment 1, 96 growing pigs with average initial body weight (BW) of 26.2 kg were used in a 25-d growth performance study. Pigs were assigned to four dietary treatments with three pigs per pen and eight replicate pens per treatment in a randomized complete block design. The four treatments were control diet (CD); CD + 2 g/kg inositol; CD + 1,000 FYT/kg phytase and CD + 3,000 FYT/kg phytase. Pigs were weighed individually every week. On day 25, blood sample was collected from one pig per pen to measure plasma metabolites concentrations. In experiment 2, 16 barrows (initial BW 34.8 ± 8.2 kg) were surgically fitted with T-cannulas. Pigs were allotted to four blocks based on BW and assigned to a quadruplicate 4 × 2 incomplete Latin square design with same four dietary treatments and two periods. Ileal digesta samples were collected from each pig on days 6 and 7 of each period to determine apparent ileal digestibility (AID) of nutrients. Phytase supplementation increased final BW and average daily gain (ADG) compared with CD (P < 0.05) with no effects on average daily feed intake (ADFI) and gain to feed (G:F) was higher in 3,000 FYT/kg phytase (P < 0.05). Inositol supplementation had no effects on growth performance. Plasma myo-inositol concentration was increased by inositol supplementation, and 3,000 FYT/kg phytase increased myo-inositol in the plasma by 97.2% (P < 0.05). Plasma P concentration was increased by 1,000 or 3,000 FYT/kg phytase with no effects on alkaline phosphatase (ALP), glucose, triglycerides (TAG), calcium (Ca), and urea concentrations. Phytase supplementation reduced (P < 0.05) the phytate-P concentration in the ileal digesta and increased the digestibility of phytate-P and total P with no effects on the AID of dry matter (DM), gross energy (GE), nitrogen (N), and Ca. In conclusion, the beneficial effects of 3,000 FYT/kg phytase on feed efficiency may due to the increased release of both myo-inositol and phosphorus (P), and may not be solely due to myo-inositol release by this level of phytase.
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Affiliation(s)
- Hang Lu
- Department of Animal Sciences, Purdue University, West Lafayette, IN
| | | | | | - Kolapo M Ajuwon
- Department of Animal Sciences, Purdue University, West Lafayette, IN
| | - Olayiwola Adeola
- Department of Animal Sciences, Purdue University, West Lafayette, IN
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31
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Zhang Z, Liu H, Liu J. Akt activation: A potential strategy to ameliorate insulin resistance. Diabetes Res Clin Pract 2019; 156:107092. [PMID: 29111280 DOI: 10.1016/j.diabres.2017.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 09/24/2017] [Accepted: 10/02/2017] [Indexed: 02/08/2023]
Abstract
Insulin resistance is a hallmark of type 2 diabetes and obesity while the mechanism remains unclear. Current therapy to treat type 2 diabetes is metformin, the 5'-monophosphate-activated protein kinase (AMPK) activator, owing to the ability to augment peripheral glucose uptake. However, metformin also displays limitations, as AMPK activation remains intact and regular in most type 2 diabetes and metformin does not seem to facilitate peripheral insulin resistance. Evidence has shown that PI3K-Akt/PKB pathway could be induced via insulin and act as an important effector. Akt/PKB is capable of inducing a great number of downstream molecules, such as translocating glucose transporters GLUTs to the cell membrane thus increase glucose uptake. Hence, any defect in Akt/PKB pathway along with the downstream molecules could lead to insulin resistance. Inositol pyrophosphates, synthesized by inositol hexakisphosphate (IP6) kinase 1 (IP6K1) and competitive with 3,4,5-bisphosphate (PIP3) to bind the PH domain of Akt/PKB, demonstrate the ability to inhibit Akt signaling. In addition, IP6K1 knockout mice present increased insulin sensitivity and obesity resistance, indicating a novel therapeutic target in confronting insulin resistance. Taken together, we conclude that Akt activation is another potential strategy to ameliorate insulin resistance.
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Affiliation(s)
- Zhengyi Zhang
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Huadong Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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32
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PRPF4 is a novel therapeutic target for the treatment of breast cancer by influencing growth, migration, invasion, and apoptosis of breast cancer cells via p38 MAPK signaling pathway. Mol Cell Probes 2019; 47:101440. [PMID: 31445970 DOI: 10.1016/j.mcp.2019.101440] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/20/2019] [Accepted: 08/22/2019] [Indexed: 01/17/2023]
Abstract
Pre-mRNA processing factor 4 (PRPF4), a core protein in U4/U6 snRNP, maintains snRNP structures by interacting with PRPF3 and cyclophilin H. Expression of the PRPF4 gene affects cell survival as well as apoptosis and is responsible for retinitis pigmentosa (RP). Proteomics analysis shows that PRPF4 may be a therapeutic target in human cancers. Nevertheless, the exact function and role of the PRPF4 gene are unclear. In this study, we assessed the expression of PRPF4 gene in human breast cancer cells. First, we confirmed that the PRPF4 gene was overexpressed in various breast cancer cell lines. Next, using breast cancer cell lines MCF7 and MDA-MB-468, we established stable cell lines with PRPF4 gene knockdown. We also performed microarray analysis to investigate molecular mechanisms underlying PRPF4 activity. All cell lines with PRPF4 gene knockdown exhibited reduced cell proliferation, remarkable reduction in anchorage-independent colony formation capacity, and reduction of PCNA protein, which is a marker cell of proliferation. Reduced expression of the PRPF4 gene induced apoptosis and changes in the expression of associated apoptotic markers in breast cancer cell lines. Knockdown of the PRPF4 gene reduced cellular capacity for migration and invasion (the key hallmarks of human cancers) and decreased the expression of genes involved in epithelial-mesenchymal transition (EMT). Microarray results showed that the expression of PPIP5K1, PPIPK2, and YWHAE genes was reduced at the transcriptional level, leading to reduced phosphorylation of p38 MAPK. These findings suggest that knockdown of PRPF4 gene slows down breast cancer progression via suppression of p38 MAPK phosphorylation. In conclusion, the PRPF4 gene plays an important role in the growth of breast cancer cells and is therefore a potential therapeutic target.
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Wilson MS, Jessen HJ, Saiardi A. The inositol hexakisphosphate kinases IP6K1 and -2 regulate human cellular phosphate homeostasis, including XPR1-mediated phosphate export. J Biol Chem 2019; 294:11597-11608. [PMID: 31186349 PMCID: PMC6663863 DOI: 10.1074/jbc.ra119.007848] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/04/2019] [Indexed: 01/08/2023] Open
Abstract
Phosphate's central role in most biochemical reactions in a living organism requires carefully maintained homeostasis. Although phosphate homeostasis in mammals has long been studied at the organismal level, the intracellular mechanisms controlling phosphate metabolism are not well-understood. Inositol pyrophosphates have emerged as important regulatory elements controlling yeast phosphate homeostasis. To verify whether inositol pyrophosphates also regulate mammalian cellular phosphate homeostasis, here we knocked out inositol hexakisphosphate kinase (IP6K) 1 and IP6K2 to generate human HCT116 cells devoid of any inositol pyrophosphates. Using PAGE and HPLC analysis, we observed that the IP6K1/2-knockout cells have nondetectable levels of the IP6-derived IP7 and IP8 and also exhibit reduced synthesis of the IP5-derived PP-IP4. Nucleotide analysis showed that the knockout cells contain increased amounts of ATP, whereas the Malachite green assay found elevated levels of free intracellular phosphate. Furthermore, [32Pi] pulse labeling experiments uncovered alterations in phosphate flux, with both import and export of phosphate being decreased in the knockout cells. Functional analysis of the phosphate exporter xenotropic and polytropic retrovirus receptor 1 (XPR1) revealed that it is regulated by inositol pyrophosphates, which can bind to its SPX domain. We conclude that IP6K1 and -2 together control inositol pyrophosphate metabolism and thereby physiologically regulate phosphate export and other aspects of mammalian cellular phosphate homeostasis.
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Affiliation(s)
- Miranda S Wilson
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Henning J Jessen
- Institute of Organic Chemistry, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
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Hauke S, Dutta AK, Eisenbeis VB, Bezold D, Bittner T, Wittwer C, Thakor D, Pavlovic I, Schultz C, Jessen HJ. Photolysis of cell-permeant caged inositol pyrophosphates controls oscillations of cytosolic calcium in a β-cell line. Chem Sci 2019; 10:2687-2692. [PMID: 30996985 PMCID: PMC6419925 DOI: 10.1039/c8sc03479f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 01/09/2019] [Indexed: 12/16/2022] Open
Abstract
β-Cells respond directly to the intracellular photochemical release of caged inositol pyrophosphate isomers with modulations of oscillations in cytosolic Ca2+.
Among many cellular functions, inositol pyrophosphates (PP-InsPs) are metabolic messengers involved in the regulation of glucose uptake, insulin sensitivity, and weight gain. However, their mechanisms of action are still poorly understood. So far, the influence of PP-InsPs on cellular metabolism has been studied by overexpression or knockout/inhibition of relevant metabolizing kinases (IP6Ks, PPIP5Ks). These approaches are, inter alia, limited by time-resolution and potential compensation mechanisms. Here, we describe the synthesis of cell-permeant caged PP-InsPs as tools to rapidly modulate intracellular levels of defined isomers of PP-InsPs in a genetically non-perturbed cellular environment. We show that caged prometabolites readily enter live cells where they are enzymatically converted into still inactive, metabolically stable, photocaged PP-InsPs. Upon light-triggered release of 5-PP-InsP5, the major cellular inositol pyrophosphate, oscillations of intracellular Ca2+ levels in MIN6 cells were transiently reduced to spontaneously recover again. In contrast, uncaging of 1-PP-InsP5, a minor cellular isomer, was without effect. These results provide evidence that PP-InsPs play an active role in regulating [Ca2+]i oscillations, a key element in triggering exocytosis and secretion in β-cells.
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Affiliation(s)
- S Hauke
- EMBL, Heidelberg , 69117 Heidelberg , Germany .
| | - A K Dutta
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - V B Eisenbeis
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - D Bezold
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - T Bittner
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - C Wittwer
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - D Thakor
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - I Pavlovic
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - C Schultz
- EMBL, Heidelberg , 69117 Heidelberg , Germany . .,OHSU , Dept. Physiology & Pharmacology , Portland , OR , USA .
| | - H J Jessen
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
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35
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Marmelstein AM, Morgan JAM, Penkert M, Rogerson DT, Chin JW, Krause E, Fiedler D. Pyrophosphorylation via selective phosphoprotein derivatization. Chem Sci 2018; 9:5929-5936. [PMID: 30079207 PMCID: PMC6050540 DOI: 10.1039/c8sc01233d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/08/2018] [Indexed: 01/13/2023] Open
Abstract
An important step in elucidating the function of protein post-translational modifications (PTMs) is gaining access to site-specifically modified, homogeneous samples for biochemical characterization. Protein pyrophosphorylation is a poorly characterized PTM, and here a chemical approach to obtain pyrophosphoproteins is reported. Photo-labile phosphorimidazolide reagents were developed for selective pyrophosphorylation, affinity-capture, and release of pyrophosphoproteins. Kinetic analysis of the reaction revealed rate constants between 9.2 × 10-3 to 0.58 M-1 s-1, as well as a striking proclivity of the phosphorimidazolides to preferentially react with phosphate monoesters over other nucleophilic side chains. Besides enabling the characterization of pyrophosphorylation on protein function, this work highlights the utility of phosphoryl groups as handles for selective protein modification for a variety of applications, such as phosphoprotein bioconjugation and enrichment.
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Affiliation(s)
- Alan M Marmelstein
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie , Robert-Rössle Str. 10 , 13125 Berlin , Germany .
- Department of Chemistry , Princeton University , Washington Road , Princeton , New Jersey 08544 , USA
| | - Jeremy A M Morgan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie , Robert-Rössle Str. 10 , 13125 Berlin , Germany .
| | - Martin Penkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie , Robert-Rössle Str. 10 , 13125 Berlin , Germany .
- Institut für Chemie , Humboldt Universität zu Berlin , Brook-Taylor-Str. 2 , 12489 Berlin , Germany
| | - Daniel T Rogerson
- Medical Research Council Laboratory of Molecular Biology , Francis Crick Avenue , Cambridge , UK
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology , Francis Crick Avenue , Cambridge , UK
| | - Eberhard Krause
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie , Robert-Rössle Str. 10 , 13125 Berlin , Germany .
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie , Robert-Rössle Str. 10 , 13125 Berlin , Germany .
- Institut für Chemie , Humboldt Universität zu Berlin , Brook-Taylor-Str. 2 , 12489 Berlin , Germany
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Inositol Hexakisphosphate Kinase-2 in Cerebellar Granule Cells Regulates Purkinje Cells and Motor Coordination via Protein 4.1N. J Neurosci 2018; 38:7409-7419. [PMID: 30006360 DOI: 10.1523/jneurosci.1165-18.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/28/2018] [Accepted: 07/10/2018] [Indexed: 11/21/2022] Open
Abstract
Inositol hexakisphosphate kinases (IP6Ks) regulate various biological processes. Among pyrophosphates generated by IP6Ks, diphosphoinositol pentakisphosphate (IP7), and bis-diphosphoinositol tetrakisphosphate have been extensively characterized. IP7 is produced in mammals by a family of inositol hexakisphosphate kinases, IP6K1, IP6K2, and IP6K3, which have distinct biological functions. We report that IP6K2 binds protein 4.1.N with high affinity and specificity. Nuclear translocation of 4.1N, which is required for its principal functions, is dependent on IP6K2. Both of these proteins are highly expressed in granule cells of the cerebellum where their interaction regulates Purkinje cell morphology and cerebellar synapses. The deletion of IP6K2 in male/female mice elicits substantial defects in synaptic influences of granule cells upon Purkinje cells as well as notable impairment of locomotor function. Moreover, the disruption of IP6K2-4.1N interactions impairs cell viability. Thus, IP6K2 and its interaction with 4.1N appear to be major determinants of cerebellar disposition and psychomotor behavior.SIGNIFICANCE STATEMENT Inositol phosphates are produced by a family of inositol hexakisphosphate kinases (IP6Ks)-IP6K1, IP6K2, and IP6K3. Of these, the physiological roles of IP6K2 in the brain have been least characterized. In the present study, we report that IP6K2 binds selectively to the neuronal protein 4.1N. Both of these proteins are highly expressed in granule cells of the cerebellum. Using IP6K2 knock-out (KO) mice, we establish that IP6K2-4.1N interactions in granule cells regulate Purkinje cell morphology, the viability of cerebellar neurons, and psychomotor behavior.
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Puhl-Rubio AC, Stashko MA, Wang H, Hardy PB, Tyagi V, Li B, Wang X, Kireev D, Jessen HJ, Frye SV, Shears SB, Pearce KH. Use of Protein Kinase-Focused Compound Libraries for the Discovery of New Inositol Phosphate Kinase Inhibitors. SLAS DISCOVERY 2018; 23:982-988. [PMID: 29842835 DOI: 10.1177/2472555218775323] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Inositol hexakisphosphate kinases (IP6Ks) regulate a myriad of cellular processes, not only through their catalytic activity (which synthesizes InsP7, a multifunctional inositol pyrophosphate signaling molecule) but also through protein-protein interactions. To further study the enzymatic function and distinguish between these different mechanisms, specific inhibitors that target IP6K catalytic activity are required. Only one IP6K inhibitor is commonly used: N2-( m-(trifluoromethyl)benzyl) N6-( p-nitrobenzyl)purine (TNP). TNP is, however, compromised by weak potency, inability to distinguish between IP6K isoenzymes, off-target activities, and poor pharmacokinetic properties. Herein, we describe a new inhibitor discovery strategy, based on the high degree of structural conservation of the nucleotide-binding sites of IP6Ks and protein kinases; we screened for novel IP6K2 inhibitors using a focused set of compounds with features known, or computationally predicted, to target nucleotide binding by protein kinases. We developed a time-resolved fluorescence resonance energy transfer (TR-FRET) assay of adenosine diphosphate (ADP) formation from adenosine triphosphate (ATP). Novel hit compounds for IP6K2 were identified and validated with dose-response curves and an orthogonal assay. None of these inhibitors affected another inositol pyrophosphate kinase, PPIP5K. Our screening strategy offers multiple IP6K2 inhibitors for future development and optimization. This approach will be applicable to inhibitor discovery campaigns for other inositol phosphate kinases.
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Affiliation(s)
- Ana C Puhl-Rubio
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Michael A Stashko
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Huanchen Wang
- 2 Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - P Brian Hardy
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Vikas Tyagi
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.,4 School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology (TIET), Patiala, Punjab, India
| | - Bing Li
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Xiaodong Wang
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Dmitri Kireev
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Henning J Jessen
- 3 Institute of Organic Chemistry, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Stephen V Frye
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Stephen B Shears
- 2 Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Kenneth H Pearce
- 1 Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
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38
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Fu C, Rojas T, Chin AC, Cheng W, Bernstein IA, Albacarys LK, Wright WW, Snyder SH. Multiple aspects of male germ cell development and interactions with Sertoli cells require inositol hexakisphosphate kinase-1. Sci Rep 2018; 8:7039. [PMID: 29728588 PMCID: PMC5935691 DOI: 10.1038/s41598-018-25468-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 04/19/2018] [Indexed: 12/30/2022] Open
Abstract
Inositol hexakisphosphate kinase-1 (IP6K1) is required for male fertility, but the underlying mechanisms have been elusive. Here, we report that IP6K1 is required for multiple aspects of male germ cell development. This development requires selective interactions between germ cells and Sertoli cells, namely apical ectoplasmic specialization. Spermiation (sperm release) requires tubulobulbar complexes. We found that the apical ectoplasmic specialization and tubulobulbar complexes were poorly formed or disrupted in IP6K1 KOs. Deletion of IP6K1 elicited several aberrations, including: 1, sloughing off of round germ cells; 2, disorientation and malformation of elongating/elongated spermatids; 3, degeneration of acrosomes; 4, defects in germ-Sertoli cell interactions and 5, failure of spermiation. Eventually the sperm cells were not released but phagocytosed by Sertoli cells leading to an absence of sperm in the epididymis.
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Affiliation(s)
- Chenglai Fu
- Department of Physiology and Pathophysiology, Tianjin Medical University, Tianjin, 300070, China. .,The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
| | - Tomas Rojas
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Alfred C Chin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Weiwei Cheng
- Division of Neuropathology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Isaac A Bernstein
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Lauren K Albacarys
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - William W Wright
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Solomon H Snyder
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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Chakraborty A. The inositol pyrophosphate pathway in health and diseases. Biol Rev Camb Philos Soc 2018; 93:1203-1227. [PMID: 29282838 PMCID: PMC6383672 DOI: 10.1111/brv.12392] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 11/28/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022]
Abstract
Inositol pyrophosphates (IPPs) are present in organisms ranging from plants, slime moulds and fungi to mammals. Distinct classes of kinases generate different forms of energetic diphosphate-containing IPPs from inositol phosphates (IPs). Conversely, polyphosphate phosphohydrolase enzymes dephosphorylate IPPs to regenerate the respective IPs. IPPs and/or their metabolizing enzymes regulate various cell biological processes by modulating many proteins via diverse mechanisms. In the last decade, extensive research has been conducted in mammalian systems, particularly in knockout mouse models of relevant enzymes. Results obtained from these studies suggest impacts of the IPP pathway on organ development, especially of brain and testis. Conversely, deletion of specific enzymes in the pathway protects mice from various diseases such as diet-induced obesity (DIO), type-2 diabetes (T2D), fatty liver, bacterial infection, thromboembolism, cancer metastasis and aging. Furthermore, pharmacological inhibition of the same class of enzymes in mice validates the therapeutic importance of this pathway in cardio-metabolic diseases. This review critically analyses these findings and summarizes the significance of the IPP pathway in mammalian health and diseases. It also evaluates benefits and risks of targeting this pathway in disease therapies. Finally, future directions of mammalian IPP research are discussed.
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Affiliation(s)
- Anutosh Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO 63104, U.S.A
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40
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Yousaf R, Gu C, Ahmed ZM, Khan SN, Friedman TB, Riazuddin S, Shears SB, Riazuddin S. Mutations in Diphosphoinositol-Pentakisphosphate Kinase PPIP5K2 are associated with hearing loss in human and mouse. PLoS Genet 2018; 14:e1007297. [PMID: 29590114 PMCID: PMC5891075 DOI: 10.1371/journal.pgen.1007297] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/09/2018] [Accepted: 03/06/2018] [Indexed: 01/07/2023] Open
Abstract
Autosomal recessive nonsyndromic hearing loss is a genetically heterogeneous disorder. Here, we report a severe-to-profound sensorineural hearing loss locus, DFNB100 on chromosome 5q13.2-q23.2. Exome enrichment followed by massive parallel sequencing revealed a c.2510G>A transition variant in PPIP5K2 that segregated with DFNB100-associated hearing loss in two large apparently unrelated Pakistani families. PPIP5Ks enzymes interconvert 5-IP7 and IP8, two key members of the inositol pyrophosphate (PP-IP) cell-signaling family. Their actions at the interface of cell signaling and bioenergetic homeostasis can impact many biological processes. The c.2510G>A transition variant is predicted to substitute a highly invariant arginine residue with histidine (p.Arg837His) in the phosphatase domain of PPIP5K2. Biochemical studies revealed that the p.Arg837His variant reduces the phosphatase activity of PPIP5K2 and elevates its kinase activity. We found that in mouse inner ear, PPIP5K2 is expressed in the cochlear and vestibular sensory hair cells, supporting cells and spiral ganglion neurons. Mice homozygous for a targeted deletion of the Ppip5k2 phosphatase domain exhibit degeneration of cochlear outer hair cells and elevated hearing thresholds. Our demonstration that PPIP5K2 has a role in hearing in humans indicates that PP-IP signaling is important to hair cell maintenance and function within inner ear. Exome sequencing coupled with homozygosity mapping was used to identify a missense variant [c.2510G>A; p.(Arg837His)] in PPIP5K2 at the DFNB100 locus that is associated with nonsyndromic, prelingual sensorineural deafness in two large consanguineous Pakistani families. PPIP5Ks are pivotal enzymes for regulating inositol pyrophosphate (PP-IP) turnover. Biochemical analyses revealed that, compared to wild type human PPIP5K2, the PPIP5K2R837H variant exhibited lower phosphatase activity and higher kinase activity, indicating that it promotes increased metabolic flux from 5-IP7 to IP8 in vivo. In rodent inner ears, PPIP5K2 immunoreactivity was observed in the cochlear and vestibular hair cells, supporting cells, and spiral ganglion neurons. Mouse mutants homozygous for the targeted deletion of Ppip5k2 phosphatase domain exhibit degeneration of cochlear outer hair cells and progressive hearing loss. Our work provides the first description of any amino acid variant of PPIP5K2 that is both functionally-significant and associates with a human disorder. The ‘futile cycling’ of the kinase/phosphatase activity of PPIP5K2 makes inner ear function particularly susceptible to even minor changes in the phosphatase activity of PPIP5K2. We have shown that a pathogenic variant in PPIP5K2 is associated with hearing loss in humans. Thus, PPIP5K2 is given new clinical significance by our observations.
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Affiliation(s)
- Rizwan Yousaf
- Laboratory of Molecular Genetics, Department of Otorhinolaryngology-Head & Neck Surgery, School of Medicine University of Maryland, Baltimore, MD, United States of America
| | - Chunfang Gu
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States of America
| | - Zubair M. Ahmed
- Laboratory of Neurogenetics and Regenerative Medicine, Department of Otorhinolaryngology-Head & Neck Surgery, School of Medicine University of Maryland, Baltimore, MD, United States of America
| | - Shaheen N. Khan
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Thomas B. Friedman
- Section on Human Genetics, Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States of America
| | - Sheikh Riazuddin
- Shaheed Zulfiqar Ali Bhutto Medical University, Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Stephen B. Shears
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States of America
| | - Saima Riazuddin
- Laboratory of Molecular Genetics, Department of Otorhinolaryngology-Head & Neck Surgery, School of Medicine University of Maryland, Baltimore, MD, United States of America
- * E-mail:
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41
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Rajasekaran SS, Kim J, Gaboardi GC, Gromada J, Shears SB, Dos Santos KT, Nolasco EL, Ferreira SDS, Illies C, Köhler M, Gu C, Ryu SH, Martins JO, Darè E, Barker CJ, Berggren PO. Inositol hexakisphosphate kinase 1 is a metabolic sensor in pancreatic β-cells. Cell Signal 2018. [PMID: 29522819 PMCID: PMC5899964 DOI: 10.1016/j.cellsig.2018.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Diphosphoinositol pentakisphosphate (IP7) is critical for the exocytotic capacity of the pancreatic β-cell, but its regulation by the primary instigator of β-cell exocytosis, glucose, is unknown. The high Km for ATP of the IP7-generating enzymes, the inositol hexakisphosphate kinases (IP6K1 and 2) suggests that these enzymes might serve as metabolic sensors in insulin secreting β-cells and act as translators of disrupted metabolism in diabetes. We investigated this hypothesis and now show that glucose stimulation, which increases the ATP/ADP ratio, leads to an early rise in IP7 concentration in β-cells. RNAi mediated knock down of the IP6K1 isoform inhibits both glucose-mediated increase in IP7 and first phase insulin secretion, demonstrating that IP6K1 integrates glucose metabolism and insulin exocytosis. In diabetic mouse islets the deranged ATP/ADP levels under both basal and glucose-stimulated conditions are mirrored in both disrupted IP7 generation and insulin release. Thus the unique metabolic sensing properties of IP6K1 guarantees appropriate concentrations of IP7 and thereby both correct basal insulin secretion and intact first phase insulin release. In addition, our data suggest that a specific cell signaling defect, namely, inappropriate IP7 generation may be an essential convergence point integrating multiple metabolic defects into the commonly observed phenotype in diabetes. Glucose increases IP7 levels transiently through IP6K1 in pancreatic β-cells. IP6K1 decodes glucose-driven increases in ATP/ADP ratio into 1st phase insulin release. IP7 production and insulin release mirror perturbed metabolism in diabetic islets. IP6K1 acts as a β-cell metabolic sensor under normal and pathological conditions.
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Affiliation(s)
- Subu Surendran Rajasekaran
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Jaeyoon Kim
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Gian-Carlo Gaboardi
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | | | - Stephen B Shears
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239,111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Karen Tiago Dos Santos
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Eduardo Lima Nolasco
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sabrina de Souza Ferreira
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Christopher Illies
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Martin Köhler
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Chunfang Gu
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239,111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Sung Ho Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Joilson O Martins
- Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elisabetta Darè
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Christopher J Barker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea.
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42
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Brown NW, Marmelstein AM, Fiedler D. Chemical tools for interrogating inositol pyrophosphate structure and function. Chem Soc Rev 2018; 45:6311-6326. [PMID: 27462803 DOI: 10.1039/c6cs00193a] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The inositol pyrophosphates (PP-InsPs) are a unique group of intracellular messengers that represent some of the most highly phosphorylated molecules in nature. Genetic perturbation of the PP-InsP biosynthetic network indicates a central role for these metabolites in maintaining cellular energy homeostasis and in controlling signal transduction networks. However, despite their discovery over two decades ago, elucidating their physiologically relevant isomers, the biochemical pathways connecting these molecules to their associated phenotypes, and their modes of signal transduction has often been stymied by technical challenges. Many of the advances in understanding these molecules to date have been facilitated by the total synthesis of the various PP-InsP isomers and by the development of new methods that are capable of identifying their downstream signalling partners. Chemical tools have also been developed to distinguish between the proposed PP-InsP signal transduction mechanisms: protein binding, and a covalent modification of proteins termed protein pyrophosphorylation. In this article, we review these recent developments, discuss how they have helped to illuminate PP-InsP structure and function, and highlight opportunities for future discovery.
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Affiliation(s)
- Nathaniel W Brown
- Princeton University, Frick Chemistry Laboratory, Washington Road, Princeton, NJ 08544, USA and Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str 10, 13125 Berlin, Berlin, Germany.
| | - Alan M Marmelstein
- Princeton University, Frick Chemistry Laboratory, Washington Road, Princeton, NJ 08544, USA and Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str 10, 13125 Berlin, Berlin, Germany.
| | - Dorothea Fiedler
- Princeton University, Frick Chemistry Laboratory, Washington Road, Princeton, NJ 08544, USA and Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str 10, 13125 Berlin, Berlin, Germany.
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43
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Wu T, Yang L, Jiang J, Ni Y, Zhu J, Zheng X, Wang Q, Lu X, Fu Z. Chronic glucocorticoid treatment induced circadian clock disorder leads to lipid metabolism and gut microbiota alterations in rats. Life Sci 2017; 192:173-182. [PMID: 29196049 DOI: 10.1016/j.lfs.2017.11.049] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/22/2017] [Accepted: 11/28/2017] [Indexed: 12/11/2022]
Abstract
AIM Glucocorticoids (GCs), steroid hormones synthetized by the adrenal gland, are regulated by circadian cycles, and dysregulation of GC signaling can lead to the development of metabolic syndrome. The effects and potential mechanism of GCs in physiology were investigated in the present study. MAIN METHODS Male Wistar rats were orally administered dexamethasone sodium phosphate (DEX, 0.01 and 0.05mg/kg body weight per day) for 7weeks. KEY FINDING DEX treatment attenuated body weight gain and reduced food intake, whereas it induced the accumulation of fat. Administration of DEX induced dysregulation of the expression of lipogenic genes in both fat and liver. Moreover, the mRNA levels of genes related to mitochondrial biogenesis and function were significantly downregulated in the liver and fat of DEX-treated rats. Furthermore, DEX treatment caused a significant reduction in the richness and diversity of the microbiota in the colon, as assessed using high-throughput sequencing of the 16s rRNA gene V3-V4 region, an increase in inflammatory cell infiltration, and a decrease in mucus secretion in the colon. Additionally, DEX administration induced phase shift or loss of circadian rhythmicity of clock-related genes in peripheral tissues. These results were associated with higher serum corticosterone levels and upregulation of GC receptor (GR) expression in peripheral tissues. SIGNIFICANCE Our findings indicate that long-term administration of GC caused lipid accumulation, changes in the structure of the intestinal flora, and reduced colonic mucus secretion in vivo. The mechanism of these physiological changes may involve a circadian rhythm disorder and dysregulation of GR expression.
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Affiliation(s)
- Tao Wu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Luna Yang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Jianguo Jiang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Yinhua Ni
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Jiawei Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Xiaojun Zheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Qi Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Xin Lu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, China.
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44
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Park SJ, Lee S, Park SE, Kim S. Inositol pyrophosphates as multifaceted metabolites in the regulation of mammalian signaling networks. Anim Cells Syst (Seoul) 2017. [DOI: 10.1080/19768354.2017.1408684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Seung Ju Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seulgi Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seung Eun Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seyun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- KAIST Institute for the BioCentury, KAIST, Daejeon, Republic of Korea
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45
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Rajasekaran SS, Illies C, Shears SB, Wang H, Ayala TS, Martins JO, Daré E, Berggren PO, Barker CJ. Protein kinase- and lipase inhibitors of inositide metabolism deplete IP 7 indirectly in pancreatic β-cells: Off-target effects on cellular bioenergetics and direct effects on IP6K activity. Cell Signal 2017; 42:127-133. [PMID: 29042286 PMCID: PMC5765549 DOI: 10.1016/j.cellsig.2017.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 12/22/2022]
Abstract
Inositol pyrophosphates have emerged as important regulators of many critical cellular processes from vesicle trafficking and cytoskeletal rearrangement to telomere length regulation and apoptosis. We have previously demonstrated that 5-di-phosphoinositol pentakisphosphate, IP7, is at a high level in pancreatic β-cells and is important for insulin exocytosis. To better understand IP7 regulation in β-cells, we used an insulin secreting cell line, HIT-T15, to screen a number of different pharmacological inhibitors of inositide metabolism for their impact on cellular IP7. Although the inhibitors have diverse targets, they all perturbed IP7 levels. This made us suspicious that indirect, off-target effects of the inhibitors could be involved. It is known that IP7 levels are decreased by metabolic poisons. The fact that the inositol hexakisphosphate kinases (IP6Ks) have a high Km for ATP makes IP7 synthesis potentially vulnerable to ATP depletion. Furthermore, many kinase inhibitors are targeted to the ATP binding site of kinases, but given the similarity of such sites, high specificity is difficult to achieve. Here, we show that IP7 concentrations in HIT-T15 cells were reduced by inhibitors of PI3K (wortmannin, LY294002), PI4K (Phenylarsine Oxide, PAO), PLC (U73122) and the insulin receptor (HNMPA). Each of these inhibitors also decreased the ATP/ADP ratio. Thus reagents that compromise energy metabolism reduce IP7 indirectly. Additionally, PAO, U73122 and LY294002 also directly inhibited the activity of purified IP6K. These data are of particular concern for those studying signal transduction in pancreatic β-cells, but also highlight the fact that employment of these inhibitors could have erroneously suggested the involvement of key signal transduction pathways in various cellular processes. Conversely, IP7’s role in cellular signal transduction is likely to have been underestimated. In pancreatic β-cells several inhibitors of signal transduction reduce IP7 levels. There is a positive correlation between IP7 reduction and decrease in ATP/ADP. Inhibitors deplete IP7 levels indirectly by decreasing ATP/ADP levels. Some purportedly specific cell-signaling inhibitors directly target IP6K activity. Caution is required in interpreting data obtained using inhibitors of inositide metabolism.
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Affiliation(s)
- Subu Surendran Rajasekaran
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Christopher Illies
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Stephen B Shears
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Huanchen Wang
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Thais S Ayala
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Joilson O Martins
- Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elisabetta Daré
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
| | - Christopher J Barker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
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46
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Malla AB, Bhandari R. IP6K1 is essential for chromatoid body formation and temporal regulation of Tnp2 and Prm2 expression in mouse spermatids. J Cell Sci 2017; 130:2854-2866. [PMID: 28743739 DOI: 10.1242/jcs.204966] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/13/2017] [Indexed: 12/25/2022] Open
Abstract
Inositol hexakisphosphate kinases (IP6Ks) are enzymes that synthesise the inositol pyrophosphate 5-diphosphoinositol pentakisphosphate (5-IP7), which is known to regulate several physiological processes. Deletion of IP6K1, but not other IP6K isoforms, causes sterility in male mice. Here, we present a detailed investigation of the specific function of IP6K1 in spermatogenesis. Within the mouse testis, IP6K1 is expressed at high levels in late stage pachytene spermatocytes and in round spermatids. We found IP6K1 to be a novel component of the chromatoid body, a cytoplasmic granule found in round spermatids that is composed of RNA and RNA-binding proteins, and noted that this structure is absent in Ip6k1-/- round spermatids. Furthermore, juvenile spermatids from Ip6k1-/- mice display premature expression of the transition protein TNP2 and the protamine PRM2 due to translational derepression. The aberrant localisation of these key sperm-specific chromatin components, together with the persistence of somatic histones, results in abnormal spermatid elongation, failure to complete spermatid differentiation and azoospermia in these mice. Our study thus identifies IP6K1 as an indispensable factor in the temporal regulation of male germ cell differentiation.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Aushaq Bashir Malla
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana 500001, India.,Graduate Studies, Manipal University, Manipal, Karnataka 576104, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana 500001, India
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Shears SB. Intimate connections: Inositol pyrophosphates at the interface of metabolic regulation and cell signaling. J Cell Physiol 2017; 233:1897-1912. [PMID: 28542902 DOI: 10.1002/jcp.26017] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 05/18/2017] [Indexed: 12/11/2022]
Abstract
Inositol pyrophosphates are small, diffusible signaling molecules that possess the most concentrated three-dimensional array of phosphate groups in Nature; up to eight phosphates are crammed around a six-carbon inositol ring. This review discusses the physico-chemical properties of these unique molecules, and their mechanisms of action. Also provided is information on the enzymes that regulate the levels and hence the signaling properties of these molecules. This review pursues the idea that many of the biological effects of inositol pyrophosphates can be rationalized by their actions at the interface of cell signaling and metabolism that is essential to cellular and organismal homeostasis.
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Affiliation(s)
- Stephen B Shears
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
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48
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Abstract
Genetic ablation of inositol pyrophosphate synthesis has established the fundamental importance of this class of molecules to the eukaryote cell. These studies, however, must be complemented by cell biology and biochemical approaches to appreciate the signalling involved in the processes regulated by inositol pyrophosphates. A recent study by Chanduri et al. published in the Biochemical Journal, by integrating multiple experimental approaches, demonstrated that inositol pyrophosphates regulate intracellular vesicular movement. In particular, the vesicular transport along the microtubule that is driven by the motor protein complex dynein. Importantly, one subunit of this cellular motor, dynein 1 intermediate chain 2, undergoes serine pyrophosphorylation, a post-translational modification driven by inositol pyrophosphates. The pyrophosphorylation status of this dynein intermediate chain regulates its interaction with dynactin, which recruits the motor to vesicles. This mechanistically might explain how inositol pyrophosphates control intracellular membrane trafficking. By dissecting the serine pyrophosphorylation process, this work increases our awareness of this modification, underappreciated by the scientific literature but probably not by the eukaryotic cell.
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49
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Penkert M, Yates LM, Schümann M, Perlman D, Fiedler D, Krause E. Unambiguous Identification of Serine and Threonine Pyrophosphorylation Using Neutral-Loss-Triggered Electron-Transfer/Higher-Energy Collision Dissociation. Anal Chem 2017; 89:3672-3680. [DOI: 10.1021/acs.analchem.6b05095] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Martin Penkert
- Leibniz Institut für Molekulare Pharmakologie (FMP), Robert-Rössle Str. 10, 13125 Berlin, Germany
- Humboldt Universität zu Berlin, Department
of Chemistry, Brook-Taylor-Straße
2, 12489 Berlin, Germany
| | - Lisa M. Yates
- Princeton University, Department of Chemistry, Frick Chemistry Building, Washington
Road, Princeton, New Jersey 08544, United States
| | - Michael Schümann
- Leibniz Institut für Molekulare Pharmakologie (FMP), Robert-Rössle Str. 10, 13125 Berlin, Germany
| | - David Perlman
- Princeton University, Department of Molecular Biology, 119 Lewis Thomas Laboratory, Washington
Road, Princeton, New Jersey 08544, United States
| | - Dorothea Fiedler
- Leibniz Institut für Molekulare Pharmakologie (FMP), Robert-Rössle Str. 10, 13125 Berlin, Germany
- Humboldt Universität zu Berlin, Department
of Chemistry, Brook-Taylor-Straße
2, 12489 Berlin, Germany
| | - Eberhard Krause
- Leibniz Institut für Molekulare Pharmakologie (FMP), Robert-Rössle Str. 10, 13125 Berlin, Germany
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50
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Shah A, Ganguli S, Sen J, Bhandari R. Inositol Pyrophosphates: Energetic, Omnipresent and Versatile Signalling Molecules. J Indian Inst Sci 2017; 97:23-40. [PMID: 32214696 PMCID: PMC7081659 DOI: 10.1007/s41745-016-0011-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 11/16/2016] [Indexed: 12/21/2022]
Abstract
Inositol pyrophosphates (PP-IPs) are a class of energy-rich signalling molecules found in all eukaryotic cells. These are derivatives of inositol that contain one or more diphosphate (or pyrophosphate) groups in addition to monophosphates. The more abundant and best studied PP-IPs are diphosphoinositol pentakisphosphate (IP7) and bis-diphosphoinositol tetrakisphosphate (IP8). These molecules can influence protein function by two mechanisms: binding and pyrophosphorylation. The former involves the specific interaction of a particular inositol pyrophosphate with a binding site on a protein, while the latter is a unique attribute of inositol pyrophosphates, wherein the β-phosphate moiety is transferred from a PP-IP to a pre-phosphorylated serine residue in a protein to generate pyrophosphoserine. Both these events can result in changes in the target protein’s activity, localisation or its interaction with other partners. As a consequence of their ubiquitous presence in all eukaryotic organisms and all cell types examined till date, and their ability to modify protein function, PP-IPs have been found to participate in a wide range of metabolic, developmental, and signalling pathways. This review highlights
many of the known functions of PP-IPs in the context of their temporal and spatial distribution in eukaryotic cells.
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Affiliation(s)
- Akruti Shah
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
- Graduate Studies, Manipal University, Manipal, Karnataka India
| | - Shubhra Ganguli
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
- Graduate Studies, Manipal University, Manipal, Karnataka India
| | - Jayraj Sen
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
- Graduate Studies, Manipal University, Manipal, Karnataka India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
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