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Pieles O, Reichert TE, Morsczeck C. Protein kinase A is activated during bone morphogenetic protein 2-induced osteogenic differentiation of dental follicle stem cells via endogenous parathyroid hormone-related protein. Arch Oral Biol 2022; 138:105409. [PMID: 35338829 DOI: 10.1016/j.archoralbio.2022.105409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/07/2022] [Accepted: 03/13/2022] [Indexed: 12/26/2022]
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2
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Mehany ABM, Belal A, Mohamed AF, Shaaban S, Abdelhamid G. Apoptotic and anti-angiogenic effects of propolis against human bladder cancer: molecular docking and in vitro screening. Biomarkers 2022; 27:138-150. [PMID: 34927500 DOI: 10.1080/1354750x.2021.2020903] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Bladder cancer is still of unknown initiation and progression, it is difficult to treat the patient once bladder cancer have a distant metastasis. MATERIALS AND METHODS In the present study, propolis extract was evaluated against bladder cancer cells (T24). Two independent pathways were investigated, apoptosis and angiogenesis, Bax, Bcl-2, P53, and caspase-3 for apoptosis, vascular endothelial growth factor receptor and protein kinase A as angiogenesis potential targets. OBJECTIVES Molecular docking studies will be conducted for the major known constituents of Egyptian propolis into apoptotic and angiogenic protein targets, to give better insights to the possible binding mode and interactions and investigate the ability of propolis constituents to target both apoptotic and angiogenic pathways. RESULTS Propolis showed anti-proliferative activity against T24 cancer cell line, the IC50 value was 6.36 µg/ml. Also significant effects of propolis on Bax, Bcl-2, P53, and caspase-3 were observed. DISCUSSION These obtained results proved the ability of propolis to induce cell death. Also it has revealed noticeable effects on protein kinase A and vascular endothelial growth factor receptor. CONCLUSION The obtained results can encourage us to say that propolis extract can induce a programmed cell death in human bladder cancer cells, and also affect angiogenesis.
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Affiliation(s)
- Ahmed B M Mehany
- Genetic Engineering, Department of Zoology, Faculty of Science Al-Azhar University, Cairo, Egypt
| | - Amany Belal
- Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University, Taif, Saudi Arabia
| | - Aly Fahmy Mohamed
- Holding Company for Production of Vaccines and Biological Products (VACSERA), Agouza, Egypt
| | - Salwa Shaaban
- Department of Microbiology& Immunology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt.,Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia
| | - Ghada Abdelhamid
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Egypt
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3
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The role of curcumin in aging and senescence: Molecular mechanisms. Biomed Pharmacother 2021; 134:111119. [DOI: 10.1016/j.biopha.2020.111119] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/29/2020] [Accepted: 12/04/2020] [Indexed: 12/11/2022] Open
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4
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Bahrami A, Bo S, Jamialahmadi T, Sahebkar A. Effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on ageing: Molecular mechanisms. Ageing Res Rev 2020; 58:101024. [PMID: 32006687 DOI: 10.1016/j.arr.2020.101024] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/11/2019] [Accepted: 01/27/2020] [Indexed: 12/15/2022]
Abstract
Human ageing is determined by degenerative alterations and processes with different manifestations such as gradual organ dysfunction, tissue function loss, increased population of aged (senescent) cells, incapability of maintaining homeostasis and reduced repair capacity, which collectively lead to an increased risk of diseases and death. The inhibitors of HMG-CoA reductase (statins) are the most widely used lipid-lowering agents, which can reduce cardiovascular morbidity and mortality. Accumulating evidence has documented several pleiotropic effects of statins in addition to their lipid-lowering properties. Recently, several studies have highlighted that statins may have the potential to delay the ageing process and inhibit the onset of senescence. In this review, we focused on the anti-ageing mechanisms of statin drugs and their effects on cardiovascular and non-cardiovascular diseases.
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5
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Zhao X, Nedvetsky P, Stanchi F, Vion AC, Popp O, Zühlke K, Dittmar G, Klussmann E, Gerhardt H. Endothelial PKA activity regulates angiogenesis by limiting autophagy through phosphorylation of ATG16L1. eLife 2019; 8:e46380. [PMID: 31580256 PMCID: PMC6797479 DOI: 10.7554/elife.46380] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 10/01/2019] [Indexed: 12/15/2022] Open
Abstract
The cAMP-dependent protein kinase A (PKA) regulates various cellular functions in health and disease. In endothelial cells PKA activity promotes vessel maturation and limits tip cell formation. Here, we used a chemical genetic screen to identify endothelial-specific direct substrates of PKA in human umbilical vein endothelial cells (HUVEC) that may mediate these effects. Amongst several candidates, we identified ATG16L1, a regulator of autophagy, as novel target of PKA. Biochemical validation, mass spectrometry and peptide spot arrays revealed that PKA phosphorylates ATG16L1α at Ser268 and ATG16L1β at Ser269, driving phosphorylation-dependent degradation of ATG16L1 protein. Reducing PKA activity increased ATG16L1 protein levels and endothelial autophagy. Mouse in vivo genetics and pharmacological experiments demonstrated that autophagy inhibition partially rescues vascular hypersprouting caused by PKA deficiency. Together these results indicate that endothelial PKA activity mediates a critical switch from active sprouting to quiescence in part through phosphorylation of ATG16L1, which in turn reduces endothelial autophagy.
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Affiliation(s)
- Xiaocheng Zhao
- Vascular Patterning Laboratory, Center for Cancer BiologyVIBLeuvenBelgium
- Vascular Patterning Laboratory, Center for Cancer Biology, Department of OncologyVIBLeuvenBelgium
| | - Pavel Nedvetsky
- Vascular Patterning Laboratory, Center for Cancer BiologyVIBLeuvenBelgium
- Vascular Patterning Laboratory, Center for Cancer Biology, Department of OncologyVIBLeuvenBelgium
- Medical Cell Biology, Medical Clinic DUniversity Hospital MünsterMünsterGermany
| | - Fabio Stanchi
- Vascular Patterning Laboratory, Center for Cancer BiologyVIBLeuvenBelgium
- Vascular Patterning Laboratory, Center for Cancer Biology, Department of OncologyVIBLeuvenBelgium
| | - Anne-Clemence Vion
- Integrative Vascular Biology LabMax-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
- INSERM UMR-970, Paris Cardiovascular Research CenterParis Descartes UniversityParisFrance
| | - Oliver Popp
- ProteomicsMax-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
| | - Kerstin Zühlke
- Anchored Signaling LabMax-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
| | - Gunnar Dittmar
- ProteomicsMax-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
- CRP Santé · Department of OncologyLIH Luxembourg Institute of HealthLuxembourgLuxembourg
| | - Enno Klussmann
- Anchored Signaling LabMax-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
- DZHK (German Center for Cardiovascular Research)BerlinGermany
| | - Holger Gerhardt
- Vascular Patterning Laboratory, Center for Cancer BiologyVIBLeuvenBelgium
- Vascular Patterning Laboratory, Center for Cancer Biology, Department of OncologyVIBLeuvenBelgium
- Integrative Vascular Biology LabMax-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
- DZHK (German Center for Cardiovascular Research)BerlinGermany
- Berlin Institute of Health (BIH)BerlinGermany
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6
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Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
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Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
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7
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Hara M, Lourido S, Petrova B, Lou HJ, Von Stetina JR, Kashevsky H, Turk BE, Orr-Weaver TL. Identification of PNG kinase substrates uncovers interactions with the translational repressor TRAL in the oocyte-to-embryo transition. eLife 2018; 7:33150. [PMID: 29480805 PMCID: PMC5826265 DOI: 10.7554/elife.33150] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 02/12/2018] [Indexed: 12/19/2022] Open
Abstract
The Drosophila Pan Gu (PNG) kinase complex regulates hundreds of maternal mRNAs that become translationally repressed or activated as the oocyte transitions to an embryo. In a previous paper (Hara et al., 2017), we demonstrated PNG activity is under tight developmental control and restricted to this transition. Here, examination of PNG specificity showed it to be a Thr-kinase yet lacking a clear phosphorylation site consensus sequence. An unbiased biochemical screen for PNG substrates identified the conserved translational repressor Trailer Hitch (TRAL). Phosphomimetic mutation of the PNG phospho-sites in TRAL reduced its ability to inhibit translation in vitro. In vivo, mutation of tral dominantly suppressed png mutants and restored Cyclin B protein levels. The repressor Pumilio (PUM) has the same relationship with PNG, and we also show that PUM is a PNG substrate. Furthermore, PNG can phosphorylate BICC and ME31B, repressors that bind TRAL in cytoplasmic RNPs. Therefore, PNG likely promotes translation at the oocyte-to-embryo transition by phosphorylating and inactivating translational repressors.
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Affiliation(s)
| | | | | | - Hua Jane Lou
- Department of Pharmacology, Yale School of Medicine, New Haven, United States
| | | | | | - Benjamin E Turk
- Department of Pharmacology, Yale School of Medicine, New Haven, United States
| | - Terry L Orr-Weaver
- Whitehead Institute, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
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8
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Zhao L, Liu J, He C, Yan R, Zhou K, Cui Q, Meng X, Li X, Zhang Y, Nie Y, Zhang Y, Hu R, Liu Y, Zhao L, Chen M, Xiao W, Tian J, Zhao Y, Cao L, Zhou L, Lin A, Ruan C, Dai K. Protein kinase A determines platelet life span and survival by regulating apoptosis. J Clin Invest 2017; 127:4338-4351. [PMID: 29083324 DOI: 10.1172/jci95109] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/21/2017] [Indexed: 11/17/2022] Open
Abstract
Apoptosis delimits platelet life span in the circulation and leads to storage lesion, which severely limits the shelf life of stored platelets. Moreover, accumulating evidence indicates that platelet apoptosis provoked by various pathological stimuli results in thrombocytopenia in many common diseases. However, little is known about how platelet apoptosis is initiated or regulated. Here, we show that PKA activity is markedly reduced in platelets aged in vitro, stored platelets, and platelets from patients with immune thrombocytopenia (ITP), diabetes, and bacterial infections. Inhibition or genetic ablation of PKA provoked intrinsic programmed platelet apoptosis in vitro and rapid platelet clearance in vivo. PKA inhibition resulted in dephosphorylation of the proapoptotic protein BAD at Ser155, resulting in sequestration of prosurvival protein BCL-XL in mitochondria and subsequent apoptosis. Notably, PKA activation protected platelets from apoptosis induced by storage or pathological stimuli and elevated peripheral platelet levels in normal mice and in a murine model of ITP. Therefore, these findings identify PKA as a homeostatic regulator of platelet apoptosis that determines platelet life span and survival. Furthermore, these results suggest that regulation of PKA activity represents a promising strategy for extending platelet shelf life and has profound implications for the treatment of platelet number-related diseases and disorders.
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Affiliation(s)
- Lili Zhao
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Jun Liu
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Chunyan He
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Rong Yan
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Kangxi Zhou
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Qingya Cui
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Xingjun Meng
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Xiaodong Li
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Yang Zhang
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Yumei Nie
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Yang Zhang
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Renping Hu
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Yancai Liu
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Lian Zhao
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China.,Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Mengxing Chen
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Weiling Xiao
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Jingluan Tian
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Yunxiao Zhao
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Lijuan Cao
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Ling Zhou
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Anning Lin
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, USA
| | - Changgeng Ruan
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
| | - Kesheng Dai
- Jiangsu Institute of Hematology, The First Affiliated Hospital and Collaborative Innovation Center of Hematology, Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China
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9
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Protein Kinase A: A Master Kinase of Granulosa Cell Differentiation. Sci Rep 2016; 6:28132. [PMID: 27324437 PMCID: PMC4914995 DOI: 10.1038/srep28132] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 06/01/2016] [Indexed: 12/16/2022] Open
Abstract
Activation of protein kinase A (PKA) by follicle stimulating hormone (FSH) transduces the signal that drives differentiation of ovarian granulosa cells (GCs). An unresolved question is whether PKA is sufficient to initiate the complex program of GC responses to FSH. We compared signaling pathways and gene expression profiles of GCs stimulated with FSH or expressing PKA-CQR, a constitutively active mutant of PKA. Both FSH and PKA-CQR stimulated the phosphorylation of proteins known to be involved in GC differentiation including CREB, ß-catenin, AKT, p42/44 MAPK, GAB2, GSK-3ß, FOXO1, and YAP. In contrast, FSH stimulated the phosphorylation of p38 MAP kinase but PKA-CQR did not. Microarray analysis revealed that 85% of transcripts that were up-regulated by FSH were increased to a comparable extent by PKA-CQR and of the transcripts that were down-regulated by FSH, 76% were also down-regulated by PKA-CQR. Transcripts regulated similarly by FSH and PKA-CQR are involved in steroidogenesis and differentiation, while transcripts more robustly up-regulated by PKA-CQR are involved in ovulation. Thus, PKA, under the conditions of our experimental approach appears to function as a master upstream kinase that is sufficient to initiate the complex pattern of intracellular signaling pathway and gene expression profiles that accompany GC differentiation.
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10
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Galac S. Cortisol-secreting adrenocortical tumours in dogs and their relevance for human medicine. Mol Cell Endocrinol 2016; 421:34-9. [PMID: 26123587 DOI: 10.1016/j.mce.2015.06.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 10/23/2022]
Abstract
Spontaneous cortisol-secreting adrenocortical tumours in pet dogs are an attractive animal model for their human counterparts. Adrenal morphology and function are similar in dogs and humans, and adrenocortical tumours have comparable clinical and pathological characteristics. Their relatively high incidence in pet dogs represents a potential source of adrenocortical tumour tissue to facilitate research. The molecular characteristics of canine cortisol-secreting adrenocortical tumours suggest that they will be useful for the study of angiogenesis, the cAMP/protein kinase A pathway, and the role of Steroidogenic Factor-1 in adrenal tumourigenesis. Pet dogs with spontaneous cortisol-secreting adrenocortical tumours may also be useful in clinical testing of new drugs and in investigating the molecular background of adrenocortical tumours.
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Affiliation(s)
- Sara Galac
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3508 TD Utrecht, The Netherlands.
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11
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Lopez MS, Kliegman JI, Shokat KM. The logic and design of analog-sensitive kinases and their small molecule inhibitors. Methods Enzymol 2015; 548:189-213. [PMID: 25399647 DOI: 10.1016/b978-0-12-397918-6.00008-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Analog-sensitive AS Kinase technology allows for rapid, reversible, and highly specific inhibition of individual engineered kinases in cells and in mouse models of human diseases. The technique consists of two parts: a kinase containing a space-creating mutation in the ATP-binding pocket and a bulky ATP-competitive small molecule inhibitor that complements the shape of the mutant ATP pocket. This strategy enables dissection of phospho-signaling pathways, elucidation of the physiological function of individual kinases, and characterization of the pharmacology of clinical-kinase inhibitors. Here, we present an overview of AS technology and describe a stepwise approach for generating AS Kinase mutants and identifying appropriate small molecule inhibitors. We also describe commonly encountered technical obstacles and provide strategies to overcome them.
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Affiliation(s)
- Michael S Lopez
- Howard Hughes Medical Institute and Department of Cellular & Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Joseph I Kliegman
- Howard Hughes Medical Institute and Department of Cellular & Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Kevan M Shokat
- Howard Hughes Medical Institute and Department of Cellular & Molecular Pharmacology, University of California, San Francisco, California, USA
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12
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Kumar V, Weng YC, Geldenhuys WJ, Wang D, Han X, Messing RO, Chou WH. Generation and characterization of ATP analog-specific protein kinase Cδ. J Biol Chem 2014; 290:1936-51. [PMID: 25505183 DOI: 10.1074/jbc.m114.598698] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To better study the role of PKCδ in normal function and disease, we developed an ATP analog-specific (AS) PKCδ that is sensitive to specific kinase inhibitors and can be used to identify PKCδ substrates. AS PKCδ showed nearly 200 times higher affinity (Km) and 150 times higher efficiency (kcat/Km) than wild type (WT) PKCδ toward N(6)-(benzyl)-ATP. AS PKCδ was uniquely inhibited by 1-(tert-butyl)-3-(1-naphthyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (1NA-PP1) and 1-(tert-butyl)-3-(2-methylbenzyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (2MB-PP1) but not by other 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP1) analogs tested, whereas WT PKCδ was insensitive to all PP1 analogs. To understand the mechanisms for specificity and affinity of these analogs, we created in silico WT and AS PKCδ homology models based on the crystal structure of PKCι. N(6)-(Benzyl)-ATP and ATP showed similar positioning within the purine binding pocket of AS PKCδ, whereas N(6)-(benzyl)-ATP was displaced from the pocket of WT PKCδ and was unable to interact with the glycine-rich loop that is required for phosphoryl transfer. The adenine rings of 1NA-PP1 and 2MB-PP1 matched the adenine ring of ATP when docked in AS PKCδ, and this interaction prevented the potential interaction of ATP with Lys-378, Glu-428, Leu-430, and Phe-633 residues. 1NA-PP1 failed to effectively dock within WT PKCδ. Other PP1 analogs failed to interact with either AS PKCδ or WT PKCδ. These results provide a structural basis for the ability of AS PKCδ to efficiently and specifically utilize N(6)-(benzyl)-ATP as a phosphate donor and for its selective inhibition by 1NA-PP1 and 2MB-PP1. Such homology modeling could prove useful in designing molecules to target PKCδ and other kinases to understand their function in cell signaling and to identify unique substrates.
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Affiliation(s)
- Varun Kumar
- From the Department of Biological Sciences, School of Biomedical Sciences, Kent State University, Kent, Ohio 44242
| | - Yi-Chinn Weng
- From the Department of Biological Sciences, School of Biomedical Sciences, Kent State University, Kent, Ohio 44242
| | - Werner J Geldenhuys
- the Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272
| | - Dan Wang
- the Ernest Gallo Clinic and Research Center, Department of Neurology, University of California, San Francisco, Emeryville, California 94608, and
| | - Xiqian Han
- From the Department of Biological Sciences, School of Biomedical Sciences, Kent State University, Kent, Ohio 44242
| | - Robert O Messing
- the Ernest Gallo Clinic and Research Center, Department of Neurology, University of California, San Francisco, Emeryville, California 94608, and the Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas, Austin, Texas 78712
| | - Wen-Hai Chou
- From the Department of Biological Sciences, School of Biomedical Sciences, Kent State University, Kent, Ohio 44242, the Ernest Gallo Clinic and Research Center, Department of Neurology, University of California, San Francisco, Emeryville, California 94608, and
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13
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Stratakis CA. E pluribus unum? The main protein kinase A catalytic subunit (PRKACA), a likely oncogene, and cortisol-producing tumors. J Clin Endocrinol Metab 2014; 99:3629-33. [PMID: 25279575 PMCID: PMC4184082 DOI: 10.1210/jc.2014-3295] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Constantine A Stratakis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH); Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, NICHD, NIH; and Inter-Institute Pediatric Endocrinology Training Program, NIH, Bethesda, Maryland 20892
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14
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Tandon M, Johnson J, Li Z, Xu S, Wipf P, Wang QJ. New pyrazolopyrimidine inhibitors of protein kinase d as potent anticancer agents for prostate cancer cells. PLoS One 2013; 8:e75601. [PMID: 24086585 PMCID: PMC3781056 DOI: 10.1371/journal.pone.0075601] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 08/18/2013] [Indexed: 12/04/2022] Open
Abstract
The emergence of protein kinase D (PKD) as a potential therapeutic target for several diseases including cancer has triggered the search for potent, selective, and cell-permeable small molecule inhibitors. In this study, we describe the identification, in vitro characterization, structure-activity analysis, and biological evaluation of a novel PKD inhibitory scaffold exemplified by 1-naphthyl PP1 (1-NA-PP1). 1-NA-PP1 and IKK-16 were identified as pan-PKD inhibitors in a small-scale targeted kinase inhibitor library assay. Both screening hits inhibited PKD isoforms at about 100 nM and were ATP-competitive inhibitors. Analysis of several related kinases indicated that 1-NA-PP1 was highly selective for PKD as compared to IKK-16. SAR analysis showed that 1-NA-PP1 was considerably more potent and showed distinct substituent effects at the pyrazolopyrimidine core. 1-NA-PP1 was cell-active, and potently blocked prostate cancer cell proliferation by inducing G2/M arrest. It also potently blocked the migration and invasion of prostate cancer cells, demonstrating promising anticancer activities on multiple fronts. Overexpression of PKD1 or PKD3 almost completely reversed the growth arrest and the inhibition of tumor cell invasion caused by 1-NA-PP1, indicating that its anti-proliferative and anti-invasive activities were mediated through the inhibition of PKD. Interestingly, a 12-fold increase in sensitivity to 1-NA-PP1 could be achieved by engineering a gatekeeper mutation in the active site of PKD1, suggesting that 1-NA-PP1 could be paired with the analog-sensitive PKD1M659G for dissecting PKD-specific functions and signaling pathways in various biological systems.
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Affiliation(s)
- Manuj Tandon
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - James Johnson
- Department of Chemistry and Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Zhihong Li
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Shuping Xu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Peter Wipf
- Department of Chemistry and Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (PW); (QJW)
| | - Qiming Jane Wang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (PW); (QJW)
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15
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Banko MR, Allen JJ, Schaffer BE, Wilker EW, Tsou P, White JL, Villén J, Wang B, Kim SR, Sakamoto K, Gygi SP, Cantley LC, Yaffe MB, Shokat KM, Brunet A. Chemical genetic screen for AMPKα2 substrates uncovers a network of proteins involved in mitosis. Mol Cell 2011; 44:878-92. [PMID: 22137581 DOI: 10.1016/j.molcel.2011.11.005] [Citation(s) in RCA: 190] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 09/03/2011] [Accepted: 11/04/2011] [Indexed: 12/15/2022]
Abstract
The energy-sensing AMP-activated protein kinase (AMPK) is activated by low nutrient levels. Functions of AMPK, other than its role in cellular metabolism, are just beginning to emerge. Here we use a chemical genetics screen to identify direct substrates of AMPK in human cells. We find that AMPK phosphorylates 28 previously unidentified substrates, several of which are involved in mitosis and cytokinesis. We identify the residues phosphorylated by AMPK in vivo in several substrates, including protein phosphatase 1 regulatory subunit 12C (PPP1R12C) and p21-activated protein kinase (PAK2). AMPK-induced phosphorylation is necessary for PPP1R12C interaction with 14-3-3 and phosphorylation of myosin regulatory light chain. Both AMPK activity and PPP1R12C phosphorylation are increased in mitotic cells and are important for mitosis completion. These findings suggest that AMPK coordinates nutrient status with mitosis completion, which may be critical for the organism's response to low nutrients during development, or in adult stem and cancer cells.
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Affiliation(s)
- Max R Banko
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
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16
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Carlson SM, White FM. Using small molecules and chemical genetics to interrogate signaling networks. ACS Chem Biol 2011; 6:75-85. [PMID: 21077690 DOI: 10.1021/cb1002834] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The limited clinical success of therapeutics targeting cellular signaling processes is due to multiple factors, including off-target effects and complex feedback regulation encoded within the signaling network. To understand these effects, chemical proteomics and chemical genetics tools have been developed to map the direct targets of kinase inhibitors, determine the network-level response to inhibitor treatment, and to infer network topology. Here we provide an overview of chemical phosphoproteomic and chemical genetic methods, including specific examples where these methods have been applied to yield biological insight regarding network structure and the system-wide effects of targeted therapeutics. The challenges and caveats associated with each method are described, along with approaches being used to resolve some of these issues. With the broad array of available techniques the next decade should see a rapid improvement in our understanding of signaling networks regulation and response to targeted perturbations, leading to more efficacious therapeutic strategies.
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Affiliation(s)
- Scott M. Carlson
- Department of Biological Engineering and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Forest M. White
- Department of Biological Engineering and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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17
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Enns LC, Pettan-Brewer C, Ladiges W. Protein kinase A is a target for aging and the aging heart. Aging (Albany NY) 2010; 2:238-43. [PMID: 20448293 PMCID: PMC2881512 DOI: 10.18632/aging.100138] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PKA is an important mediator of signal transduction downstream of G-protein-coupled receptors and plays a key role in the regulation of metabolism and triglyceride storage. It is a ubiquitous cellular kinase that phosphorylates serine and threonine residues in response to cAMP. PKA consists of two regulatory subunits, RI and RII, that are activated by cAMP to release two catalytic subunits, Calpha and Cbeta. We have shown that C57/BL6J male mice lacking the regulatory RIIbeta subunit have extended lifespan and are resistant to age-related conditions including cardiac decline. In addition to being protected from diet-induced pathologies, PKA Cbeta null mutant mice are protected from age-related problems such as weight gain and enlarged livers, as well as cardiac dysfunction and hypertrophy. Several possible mechanisms for the age sparing effects of PKA inhibition are discussed including A kinase anchoring protein signaling, alterations in the beta-adrenergic pathway, and activation of AMPK. Since PKA is a major metabolic regulator of gene signaling, the human gene homologs are potential pharmacological targets for age-related conditions including heart disease associated with declining cardiac performance.
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Affiliation(s)
- Linda C Enns
- Department of Comparative Medicine, School of Medicine, University of Washington, Seattle, WA 98195, USA
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18
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Enns LC, Ladiges W. Protein kinase A signaling as an anti-aging target. Ageing Res Rev 2010; 9:269-72. [PMID: 20188216 DOI: 10.1016/j.arr.2010.02.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 02/10/2010] [Accepted: 02/17/2010] [Indexed: 01/25/2023]
Abstract
Protein kinase A (PKA) is a multi-unit protein kinase that mediates signal transduction of G-protein-coupled receptors through its activation by adenyl cyclase (AC)-mediated cAMP. The vital importance of PKA signaling to cellular function is reflected in the widespread expression of PKA subunit genes. As one of its many functions, PKA plays a key role in the regulation of metabolism and triglyceride storage. The PKA pathway has become of great interest to the study of aging, since mutations that cause a reduction in PKA signaling have been shown to extend lifespan in yeast, and to both delay the incidence and severity of age-related disease, and to promote leanness and longevity, in mice. There is increasing interest in the potential for the inhibition or redistribution of adiposity to attenuate aging, since obesity is associated with impaired function of most organ systems, and is a strong risk factor for shortened life span. Its association with coronary heart disease, hypertension, type 2 diabetes, cancer, sleep apnea and osteoarthritis is leading to its accession as a major cause of global ill health. Therefore, gene signaling pathways such as PKA that promote adiposity are potential inhibitory targets for aging intervention. Since numerous plant compounds have been found that both prevent adipogenesis and inhibit PKA signaling, a focused investigation into their effects on biological systems and the corresponding molecular mechanisms would be of high relevance to the discovery of novel and non-toxic compounds that promote healthy aging.
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19
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Koch A, Hauf S. Strategies for the identification of kinase substrates using analog-sensitive kinases. Eur J Cell Biol 2010; 89:184-93. [PMID: 20061049 DOI: 10.1016/j.ejcb.2009.11.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Phosphorylation of proteins is a prevalent post-translational modification, which affects intracellular signaling in many ways. About 2% of all eukaryotic genes code for protein kinases catalyzing phosphorylation events. Despite technological advances that have made it possible to identify thousands of phosphorylation sites simultaneously, identification of the substrates of a given kinase remains an exceptionally challenging task. Here, we summarize approaches for substrate identification that make use of genetically engineered 'analog-sensitive' kinases.
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Affiliation(s)
- André Koch
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstrasse 39, 72076 Tübingen, Germany
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20
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Tissue-specific PKA inhibition using a chemical genetic approach and its application to studies on sperm capacitation. Proc Natl Acad Sci U S A 2008; 105:20740-5. [PMID: 19074277 DOI: 10.1073/pnas.0810971105] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Studies on cAMP signaling and protein kinase A (PKA) function in vivo are limited by the lack of highly specific inhibitors that can be used in primary cell culture and whole animals. Previously we reported that a mutation in the ATP binding pocket of a catalytic subunit (Calpha) of PKA confers sensitivity to the pyrazolo[3,4-d]pyrimidine inhibitor, 1NM-PP1. We have now engineered the mouse Pkraca gene such that after Cre-mediated recombination in vivo, the CalphaM120A mutant protein is expressed and the wild-type Calpha is turned off. We demonstrate the utility of this approach by examining the requirement for PKA activity during capacitation of sperm from mice that express CalphaM120A mutant protein. For CalphaM120A sperm, 10 microM of 1NM-PP1 prevented PKA-dependent phosphorylation and the activation of motility that are both rapidly (<90 s) evoked by the HCO(3)(-) anion. A continuous (90 min) inhibition with 10 microM of 1NM-PP1 prevented the protein tyrosine phosphorylation of late-stage capacitation. Delayed application of 1NM-PP1 demonstrated that PKA activity was required for at least the initial 30 min of capacitation to produce subsequent protein tyrosine phosphorylation. Acute application of 1NM-PP1 rapidly slowed the accelerated beat of activated motility but did not affect the established waveform asymmetry of hyperactivated sperm. Our results demonstrate that PKA in CalphaM120A mutant sperm is rapidly and reversibly inhibited by 1NM-PP1 and that this blockade has selective and time-dependent effects on multiple aspects of capacitation. The conditional CalphaM120A-expressing mouse lines will be valuable tools for studying PKA function in vivo.
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21
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Gametogenesis in malaria parasites is mediated by the cGMP-dependent protein kinase. PLoS Biol 2008; 6:e139. [PMID: 18532880 PMCID: PMC2408617 DOI: 10.1371/journal.pbio.0060139] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 04/25/2008] [Indexed: 11/19/2022] Open
Abstract
Malaria parasite transmission requires differentiation of male and female gametocytes into gametes within a mosquito following a blood meal. A mosquito-derived molecule, xanthurenic acid (XA), can trigger gametogenesis, but the signalling events controlling this process in the human malaria parasite Plasmodium falciparum remain unknown. A role for cGMP was revealed by our observation that zaprinast (an inhibitor of phosphodiesterases that hydrolyse cGMP) stimulates gametogenesis in the absence of XA. Using cGMP-dependent protein kinase (PKG) inhibitors in conjunction with transgenic parasites expressing an inhibitor-insensitive mutant PKG enzyme, we demonstrate that PKG is essential for XA- and zaprinast-induced gametogenesis. Furthermore, we show that intracellular calcium (Ca2+) is required for differentiation and acts downstream of or in parallel with PKG activation. This work defines a key role for PKG in gametogenesis, elucidates the hierarchy of signalling events governing this process in P. falciparum, and demonstrates the feasibility of selective inhibition of a crucial regulator of the malaria parasite life cycle. The protozoan parasite Plasmodium falciparum, which causes malaria in humans, is responsible for over 1 million deaths each year. Its life cycle is complex; the asexually replicating forms, which cause disease symptoms, are quite distinct from the sexual forms, which mediate transmission between individuals via the bite of a mosquito. After a period of growth in the human host, these sexual forms (gametocytes) lie dormant until taken up by a mosquito. The change in environment from human to mosquito triggers differentiation into mature gametes. In this study, we have identified a protein kinase from the parasite that is instrumental in mediating this essential differentiation step. We have also gained insight into how this protein kinase might interact with calcium to coordinate these events. By using genetically modified malaria parasites in combination with specific inhibitors of the protein kinase, we have illustrated the feasibility of blocking development of the sexual stage of the parasite's life cycle. Development of a drug that targets this parasite stage, for use in combination with a curative drug, would be an important tool for controlling the spread of drug resistance. We show that differentiation of malaria parasites in response to environmental signals encountered upon entering the mosquito following a blood meal is mediated by the parasite cGMP-dependent protein kinase.
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22
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Analysis of 3-phosphoinositide-dependent kinase-1 signaling and function in ES cells. Exp Cell Res 2008; 314:2299-312. [PMID: 18514190 DOI: 10.1016/j.yexcr.2008.04.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 04/15/2008] [Accepted: 04/16/2008] [Indexed: 11/20/2022]
Abstract
3-phosphoinositide-dependent kinase-1 (PDK1) phosphorylates and activates several kinases in the cAMP-dependent, cGMP-dependent and protein kinase C (AGC) family. Many putative PDK1 substrates have been identified, but have not been analyzed following transient and specific inhibition of PDK1 activity. Here, we demonstrate that a previously characterized PDK1 inhibitor, BX-795, shows biological effects that are not consistent with PDK1 inhibition. Therefore, we describe the creation and characterization of a PDK1 mutant, L159G, which can bind inhibitor analogues containing bulky groups that hinder access to the ATP binding pocket of wild type (WT) kinases. When expressed in PDK1(-/-) ES cells, PDK1 L159G restored phosphorylation of PDK1 targets known to be hypophosphorylated in these cells. Screening of multiple inhibitor analogues showed that 1-NM-PP1 and 3,4-DMB-PP1 optimally inhibited the phosphorylation of PDK1 targets in PDK1(-/-) ES cells expressing PDK1 L159G but not WT PDK1. These compounds confirmed previously assumed PDK1 substrates, but revealed distinct dephosphorylation kinetics. While PDK1 inhibition had little effect on cell growth, it sensitized cells to apoptotic stimuli. Furthermore, PDK1 loss abolished growth of allograft tumors. Taken together we describe a model system that allows for acute and reversible inhibition of PDK1 in cells, to probe biochemical and biological consequences.
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23
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Kennedy EJ, Ghosh G, Pillus L. Identification of functionally distinct regions that mediate biological activity of the protein kinase a homolog Tpk2. J Biol Chem 2007; 283:1084-93. [PMID: 17971450 DOI: 10.1074/jbc.m704028200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kinases regulate key signaling processes that are increasingly implicated in development and disease. Kinase modulators have become important therapeutic tools and often target catalytic domains that are among the most structurally and functionally conserved regions of these enzymes. Such therapies lose efficacy as mutations conferring resistance arise. Because interactions between distinct and often distant regions of kinases can be critical, we took an unbiased genetic approach to identify sites within the protein kinase A homolog Tpk2 that contribute to its biological activity. Because many of these map outside the conserved core, this approach should be broadly useful in identifying new, more kinase-specific therapeutic targets.
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Affiliation(s)
- Eileen J Kennedy
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0375, USA
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24
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Differential effects of phosphorylation on DNA binding properties of N Oct-3 are dictated by protein/DNA complex structures. J Mol Biol 2007; 370:687-700. [PMID: 17543985 DOI: 10.1016/j.jmb.2007.04.072] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 03/22/2007] [Accepted: 04/29/2007] [Indexed: 10/23/2022]
Abstract
N Oct-3, a transcription factor member of the POU protein family, is implicated in normal central nervous system development but also in melanoma growth. Its DNA-binding domain (DBD) comprises two subdomains, POUs and POUh, joined by a linker peptide. We have previously shown that N Oct-3 can interact with the already described PORE and MORE DNA motifs, but also with a new structural element we have termed NORE. Having observed that both the PORE and NORE DNA-association modes depend on a strong anchoring of the POUh subdomain rigid arm into the DNA-target minor groove, in contrast to the MORE mode, we have formulated the hypothesis that phosphorylation of the conserved Ser101 residue located in the N Oct-3 POUh arm could lead to differential results in DNA binding according to the type of target. Here we demonstrate that, in vitro, Ser101 is phosphorylated by protein kinase A (PKA), either purified or contained in melanoma (624 mel) nuclear extract, and that this phosphorylation indeed significantly reduced N Oct-3 DBD binding to PORE and NORE motifs, most likely by hampering the POUh rigid arm insertion in the DNA minor groove. Conversely, no effect was observed on the binding of N Oct-3 DBD to MORE sequences. Finally, once bound to its DNA targets, N Oct-3 DBD is less susceptible to PKA activity. We conclude that transcription of genes exhibiting a MORE motif in their promoter should be less affected by N Oct-3 phosphorylation than that of genes switched on by PORE or NORE sequences.
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25
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Schauble S, King CC, Darshi M, Koller A, Shah K, Taylor SS. Identification of ChChd3 as a novel substrate of the cAMP-dependent protein kinase (PKA) using an analog-sensitive catalytic subunit. J Biol Chem 2007; 282:14952-9. [PMID: 17242405 DOI: 10.1074/jbc.m609221200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Due to the numerous kinases in the cell, many with overlapping substrates, it is difficult to find novel substrates for a specific kinase. To identify novel substrates of cAMP-dependent protein kinase (PKA), the PKA catalytic subunit was engineered to accept bulky N(6)-substituted ATP analogs, using a chemical genetics approach initially pioneered with v-Src (1). Methionine 120 was mutated to glycine in the ATP-binding pocket of the catalytic subunit. To express the stable mutant C-subunit in Escherichia coli required co-expression with PDK1. This mutant protein was active and fully phosphorylated on Thr(197) and Ser(338). Based on its kinetic properties, the engineered C-subunit preferred N(6)(benzyl)-ATP and N(6)(phenethyl)-ATP over other ATP analogs, but still retained a 30 microm K(m) for ATP. This mutant recombinant C-subunit was used to identify three novel PKA substrates. One protein, a novel mitochondrial ChChd protein, ChChd3, was identified, suggesting that PKA may regulate mitochondria proteins.
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Affiliation(s)
- Sharmin Schauble
- Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093-0654, USA
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26
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Cranston AN, Carniti C, Oakhill K, Radzio-Andzelm E, Stone EA, McCallion AS, Hodgson S, Clarke S, Mondellini P, Leyland J, Pierotti MA, Whittaker J, Taylor SS, Bongarzone I, Ponder BAJ. RET is constitutively activated by novel tandem mutations that alter the active site resulting in multiple endocrine neoplasia type 2B. Cancer Res 2006; 66:10179-87. [PMID: 17047083 DOI: 10.1158/0008-5472.can-06-0884] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Constitutive activation of the RET receptor tyrosine kinase underlies the genesis and progression of multiple endocrine neoplasia type 2 (MEN 2), a dominantly inherited cancer predisposition. Importantly, although kinase activation represents a common theme in neoplasias, not all activating mutations are functionally equivalent. Consistent with this, we ascertained a patient with classical features of MEN 2B, but lacking either of the classical mutations in RET (M918T or A883F). Instead, the patient harbors a novel pair of germ line missense mutations in cis at codons 804 and 805. We evaluated the potential physiochemical effects of these substitutions in silico, predicting both to be moderately deleterious in isolation, but severely deleterious in combination. Consistent with this postulate, we show that the identified tandem mutations (V804M/E805K) are biologically active, transforming cells in culture and that their transforming capacity in combination is distinctly synergistic. Furthermore, the V804M/E805K tandem lesion confers resistance to the small molecule receptor tyrosine kinase inhibitor, PP1, suggesting a mode of action distinct from that known for classical MEN 2B mutations. To address this question, we used homology molecular modeling in silico to model the active site of RET. We predict that RET804 constitutes a critical gatekeeper residue that, when mutated in combination with RET805, induces a conformational change in the hinge region that locks the active site in a position permissive for ATP hydrolysis. Our findings have implications both in the clinic and in the successful development of novel kinase-targeted anticancer drugs.
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Affiliation(s)
- Aaron N Cranston
- Cancer Research UK Department of Oncology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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27
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Boehr DD, Farley AR, LaRonde FJ, Murdock TR, Wright GD, Cox JR. Establishing the principles of recognition in the adenine-binding region of an aminoglycoside antibiotic kinase [APH(3')-IIIa]. Biochemistry 2005; 44:12445-53. [PMID: 16156657 DOI: 10.1021/bi051085p] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The protein-based molecular recognition of the adenine ring has implications throughout biological systems. In this paper, we discuss the adenine-binding region of an aminoglycoside antibiotic kinase [APH(3')-IIIa], which serves as an excellent model system for proteins that bind the adenine ring. This enzyme employs a hydrogen-bonding network involving water molecules along with enzyme backbone/side-chain atoms and a pi-pi stacking interaction to recognize the adenine ring. Our approach utilized site-directed mutagenesis, adenosine analogues and a variety of biophysical methods to probe the contacts in the adenine-binding region of APH(3')-IIIa. The results point to the polar nature of an adenine-Met90 contact in this binding pocket and the important role that Met90, the "gatekeeper" residue in structurally similar Ser/Thr protein kinases, plays in adenine binding. The results also suggest that small changes in the structure of the adenine ring can lead to significant changes in the ability of these analogues to occupy the adenine-binding region of the enzyme. Additional computational experiments indicate that both size and electronic factors are important in the binding of aromatic systems in this interaction-rich pocket. The principles governing adenine recognition established in this study may be applied to other protein-ligand complexes and used to navigate future studies directed at discovering potent and selective inhibitors of APH-type enzymes.
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Affiliation(s)
- David D Boehr
- Antimicrobial Research Centre, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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28
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Kenski DM, Zhang C, von Zastrow M, Shokat KM. Chemical genetic engineering of G protein-coupled receptor kinase 2. J Biol Chem 2005; 280:35051-61. [PMID: 16081410 DOI: 10.1074/jbc.m507594200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptor kinases (GRKs) play a pivotal role in receptor regulation. Efforts to study the acute effects of GRKs in intact cells have been limited by a lack of specific inhibitors. In the present study we have developed an engineered version of GRK2 that is specifically and reversibly inhibited by the substituted nucleotide analog 1-naphthyl-PP1 (1Na-PP1), and we explored GRK2 function in regulated internalization of the mu-opioid receptor (muOR). A previously described method that conferred analog sensitivity on various kinases, by introducing a space-creating mutation in the conserved active site, failed when applied to GRK2 because the corresponding mutation (L271G) rendered the mutant kinase (GRK2-as1) catalytically inactive. A sequence homology-based approach was used to design second-site suppressor mutations. A C221V second-site mutation produced a mutant kinase (GRK2-as5) with full functional activity and analog sensitivity as compared with wild-type GRK2 in vitro and in intact cells. The role of GRK2-as5 activity in the membrane trafficking of the muOR was also characterized. Morphine-induced internalization was completely blocked when GRK2-as5 activity was inhibited before morphine application. However, inhibition of GRK2-as5 during recycling and reinternalization of the muOR did not attenuate these processes. These results suggest there is a difference in the GRK requirement for initial ligand-induced internalization of a G protein-coupled receptor compared with subsequent rounds of reinternalization.
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Affiliation(s)
- Denise M Kenski
- Chemistry and Chemical Biology Graduate Program, Department of Psychiatry, University of California, San Francisco, California 94143, USA
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29
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Zhang C, Kenski DM, Paulson JL, Bonshtien A, Sessa G, Cross JV, Templeton DJ, Shokat KM. A second-site suppressor strategy for chemical genetic analysis of diverse protein kinases. Nat Methods 2005; 2:435-41. [PMID: 15908922 DOI: 10.1038/nmeth764] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Accepted: 04/25/2005] [Indexed: 11/08/2022]
Abstract
Chemical genetic analysis of protein kinases involves engineering kinases to be uniquely sensitive to inhibitors and ATP analogs that are not recognized by wild-type kinases. Despite the successful application of this approach to over two dozen kinases, several kinases do not tolerate the necessary modification to the ATP binding pocket, as they lose catalytic activity or cellular function upon mutation of the 'gatekeeper' residue that governs inhibitor and nucleotide substrate specificity. Here we describe the identification of second-site suppressor mutations to rescue the activity of 'intolerant' kinases. A bacterial genetic selection for second-site suppressors using an aminoglycoside kinase APH(3')-IIIa revealed several suppressor hotspots in the kinase domain. Informed by results from this selection, we focused on the beta sheet in the N-terminal subdomain and generated a structure-based sequence alignment of protein kinases in this region. From this alignment, we identified second-site suppressors for several divergent kinases including Cdc5, MEKK1, GRK2 and Pto. The ability to identify second-site suppressors to rescue the activity of intolerant kinases should facilitate chemical genetic analysis of the majority of protein kinases in the genome.
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Affiliation(s)
- Chao Zhang
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, 600 16th Street, San Francisco, California 94143-2280, USA
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30
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Jacobson KA, Ohno M, Duong HT, Kim SK, Tchilibon S, Cesnek M, Holý A, Gao ZG. A neoceptor approach to unraveling microscopic interactions between the human A2A adenosine receptor and its agonists. CHEMISTRY & BIOLOGY 2005; 12:237-47. [PMID: 15734651 PMCID: PMC3122079 DOI: 10.1016/j.chembiol.2004.12.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Revised: 11/10/2004] [Accepted: 12/14/2004] [Indexed: 12/01/2022]
Abstract
Strategically mutated neoceptors, e.g., with anionic residues in TMs 3 and 7 intended for pairing with positively charged amine-modified nucleosides, were derived from the antiinflammatory A(2A) adenosine receptor (AR). Adenosine derivatives functionalized at the 5', 2, and N(6) positions were synthesized. The T88D mutation selectively enhanced the binding of the chain-length-optimized 5'-(2-aminoethyl)uronamide but not 5'-(2-hydroxyethyl)uronamide, suggesting a critical role of the positively charged amine. Combination of this modification with the N(6)-(2-methylbenzyl) group enhanced affinity at the Q89D- and N181D- but not the T88D-A(2A)AR. Amino groups placed near the 2- or N(6)-position only slightly affected the binding to mutant receptors. The 5'-hydrazide MRS3412 was 670- and 161-fold enhanced, in binding and functionally, respectively, at the Q89D-A(2A)AR compared to the wild-type. Thus, we identified and modeled pairs of A(2A)AR-derived neoceptor-neoligand, which are pharmacologically orthogonal with respect to the native species.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Wong S, McLaughlin J, Cheng D, Zhang C, Shokat KM, Witte ON. Sole BCR-ABL inhibition is insufficient to eliminate all myeloproliferative disorder cell populations. Proc Natl Acad Sci U S A 2004; 101:17456-61. [PMID: 15505216 PMCID: PMC524218 DOI: 10.1073/pnas.0407061101] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protein kinase inhibitors can be effective in treating selected cancers, but most suppress several kinases. Imatinib mesylate has been useful in the treatment of Philadelphia chromosome-positive chronic myelogenous leukemia and B cell acute lymphoblastic leukemia through the inhibition of BCR-ABL tyrosine kinase activity. Imatinib mesylate has also been shown to inhibit KIT, ARG, and platelet-derived growth factor receptors alpha and beta, and potentially other tyrosine kinases. We have produced a mutant allele of BCR-ABL (T315A) that is uniquely inhibitable by the small molecule 4-amino-1-tert-butyl-3-(1-naphthyl)pyrazolo[3,4-d]pyrimidine and used it to demonstrate that sole suppression of BCR-ABL activity was insufficient to eliminate BCR-ABL(+) KIT(+)-expressing immature murine myeloid leukemic cells. In contrast, imatinib mesylate effectively eliminated BCR-ABL(+) KIT(+)-expressing leukemic cells. In the cellular context of mature myeloid cells and Pro/Pre B cells that do not express KIT, monospecific BCR-ABL inhibition was quantitatively as effective as imatinib mesylate in suppressing cell growth and inducing apoptosis. These results suggest that the therapeutic effectiveness of small molecule drugs such as imatinib mesylate could be due to the inhibitor's ability to suppress protein kinases in addition to the dominant target.
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Affiliation(s)
- S Wong
- Molecular Biology Interdepartmental Ph.D. Program, University of California-Los Angeles, Los Angeles, CA 90095, USA
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Ubersax JA, Woodbury EL, Quang PN, Paraz M, Blethrow JD, Shah K, Shokat KM, Morgan DO. Targets of the cyclin-dependent kinase Cdk1. Nature 2003; 425:859-64. [PMID: 14574415 DOI: 10.1038/nature02062] [Citation(s) in RCA: 703] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2003] [Accepted: 09/19/2003] [Indexed: 01/17/2023]
Abstract
The events of cell reproduction are governed by oscillations in the activities of cyclin-dependent kinases (Cdks). Cdks control the cell cycle by catalysing the transfer of phosphate from ATP to specific protein substrates. Despite their importance in cell-cycle control, few Cdk substrates have been identified. Here, we screened a budding yeast proteomic library for proteins that are directly phosphorylated by Cdk1 in whole-cell extracts. We identified about 200 Cdk1 substrates, several of which are phosphorylated in vivo in a Cdk1-dependent manner. The identities of these substrates reveal that Cdk1 employs a global regulatory strategy involving phosphorylation of other regulatory molecules as well as phosphorylation of the molecular machines that drive cell-cycle events. Detailed analysis of these substrates is likely to yield important insights into cell-cycle regulation.
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Affiliation(s)
- Jeffrey A Ubersax
- Department of Physiology, University of California, San Francisco, California 94143, USA
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