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Gao J, You T, Liu J, Yang L, Liu Y, Wang Y. TIPRL, a Potential Double-edge Molecule to be Targeted and Re-targeted Toward Cancer. Cell Biochem Biophys 2024:10.1007/s12013-024-01334-5. [PMID: 38888871 DOI: 10.1007/s12013-024-01334-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2024] [Indexed: 06/20/2024]
Abstract
The target of rapamycin (TOR) proteins exhibits phylogenetic conservation across various species, ranging from yeast to humans, and are classified as members of the phosphatidylinositol kinase (PIK)-related kinase family. Multiple serine/threonine (Ser/Thr) protein phosphatases (PP)2A, PP4, and PP6, have been recognized as constituents of the TOR signaling pathway in mammalian cells. The protein known as TOR signaling pathway regulator-like (TIPRL) functions as a regulatory agent by impeding the activity of the catalytic subunits of PP2A. Various cellular contexts have been postulated for TIPRL, encompassing the regulation of mechanistic target of rapamycin (mTOR) signaling, inhibition of apoptosis and biogenesis, and recycling of PP2A. According to reports, there has been an observed increase in TIPRL levels in several types of carcinomas, such as non-small-cell lung carcinoma (NSCLC) and hepatocellular carcinomas (HCC). This review aims to comprehensively examine the significance of the Tor pathway in regulating apoptosis and proliferation of cancer cells, with a specific focus on the role of TOR signaling and TIPRL in cancer.
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Affiliation(s)
- Jie Gao
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Tiantian You
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Jiao Liu
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Lili Yang
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Yan Liu
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Yanyan Wang
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China.
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2
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Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [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: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
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Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
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3
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Wang M, Liu J, Liao X, Yi Y, Xue Y, Yang L, Cheng H, Liu P. The SGK3-Catalase antioxidant signaling axis drives cervical cancer growth and therapy resistance. Redox Biol 2023; 67:102931. [PMID: 37866161 PMCID: PMC10623367 DOI: 10.1016/j.redox.2023.102931] [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: 08/23/2023] [Revised: 10/05/2023] [Accepted: 10/10/2023] [Indexed: 10/24/2023] Open
Abstract
Cancer cells frequently exhibit aberrant redox homeostasis and adaptation to oxidative stress. Hence abrogation of redox adaptation in cancer cells can be exploited for therapeutic benefit. Here we report SGK3 functions as an anti-oxidative factor to promote cell growth and drug resistance in cervical cancers harboring PIK3CA helical domain mutations. Mechanistically, SGK3 is activated upon oxidative stress and exerts anti-ROS activity by stabilizing and activating the antioxidant enzyme catalase. SGK3 interacts with and phosphorylates catalase, promoting its tetrameric state and activity. Meanwhile, SGK3 phosphorylates GSK3β and protects catalase from GSK3β-β-TrCP mediated ubiquitination and proteasomal degradation. Furthermore, SGK3 inhibition not only potentiates CDK4/6 inhibitor Palbociclib-mediated cytotoxicity, but also overcomes cisplatin resistance through ROS-mediated mechanisms. These data uncover the role of SGK3 in maintaining redox homeostasis and suggest that the SGK3-catalase antioxidant signaling axis may be therapeutically targeted to improve treatment efficacy for cervical cancers carrying PIK3CA helical domain mutations.
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Affiliation(s)
- Min Wang
- Cancer Institute, The Second Hospital of Dalian Medical University, Dalian Key Laboratory of Molecular Targeted Cancer Therapy, Dalian, China
| | - Jiannan Liu
- Cancer Institute, The Second Hospital of Dalian Medical University, Dalian Key Laboratory of Molecular Targeted Cancer Therapy, Dalian, China
| | - Xingming Liao
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning Province, China
| | - Yasong Yi
- Cancer Institute, The Second Hospital of Dalian Medical University, Dalian Key Laboratory of Molecular Targeted Cancer Therapy, Dalian, China
| | - Yijue Xue
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning Province, China
| | - Ling Yang
- School of Pharmacy, Zunyi Medical University, Zunyi, China; Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China; Department of Pharmacology, Key Laboratory of Basic Pharmacology of Guizhou Province, Zunyi Medical University, Zunyi, China.
| | - Hailing Cheng
- Cancer Institute, The Second Hospital of Dalian Medical University, Dalian Key Laboratory of Molecular Targeted Cancer Therapy, Dalian, China.
| | - Pixu Liu
- Cancer Institute, The Second Hospital of Dalian Medical University, Dalian Key Laboratory of Molecular Targeted Cancer Therapy, Dalian, China; Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning Province, China; Key Laboratory of Diagnosis and Treatment of Severe Hepato-Pancreatic Diseases of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.
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4
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Safaroghli-Azar A, Sanaei MJ, Pourbagheri-Sigaroodi A, Bashash D. Phosphoinositide 3-kinase (PI3K) classes: From cell signaling to endocytic recycling and autophagy. Eur J Pharmacol 2023:175827. [PMID: 37269974 DOI: 10.1016/j.ejphar.2023.175827] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/19/2023] [Accepted: 05/31/2023] [Indexed: 06/05/2023]
Abstract
Lipid signaling is defined as any biological signaling action in which a lipid messenger binds to a protein target, converting its effects to specific cellular responses. In this complex biological pathway, the family of phosphoinositide 3-kinase (PI3K) represents a pivotal role and affects many aspects of cellular biology from cell survival, proliferation, and migration to endocytosis, intracellular trafficking, metabolism, and autophagy. While yeasts have a single isoform of phosphoinositide 3-kinase (PI3K), mammals possess eight PI3K types divided into three classes. The class I PI3Ks have set the stage to widen research interest in the field of cancer biology. The aberrant activation of class I PI3Ks has been identified in 30-50% of human tumors, and activating mutations in PIK3CA is one of the most frequent oncogenes in human cancer. In addition to indirect participation in cell signaling, class II and III PI3Ks primarily regulate vesicle trafficking. Class III PI3Ks are also responsible for autophagosome formation and autophagy flux. The current review aims to discuss the original data obtained from international research laboratories on the latest discoveries regarding PI3Ks-mediated cell biological processes. Also, we unravel the mechanisms by which pools of the same phosphoinositides (PIs) derived from different PI3K types act differently.
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Affiliation(s)
- Ava Safaroghli-Azar
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad-Javad Sanaei
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Pourbagheri-Sigaroodi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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MicroRNA-377: A therapeutic and diagnostic tumor marker. Int J Biol Macromol 2023; 226:1226-1235. [PMID: 36442575 DOI: 10.1016/j.ijbiomac.2022.11.236] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/15/2022] [Accepted: 11/18/2022] [Indexed: 11/26/2022]
Abstract
Cancer is considered as one of the main causes of human deaths globally. Despite the recent progresses in therapeutic modalities, there is still a high rate of mortality among cancer patients. Late diagnosis in advanced tumor stages is one of the main reasons for treatment failure in cancer patients. Therefore, it is required to suggest the novel strategies for the early tumor detection. MicroRNAs (miRNAs) have critical roles in neoplastic transformation by regulation of cell proliferation, migration, and apoptosis. They are always considered as non-invasive markers due to their high stability in body fluids. Since, all of the miRNAs have tissue-specific functions in different tumors as tumor suppressor or oncogene; it is required to investigate the molecular mechanisms of every miRNA in different tumors to introduce that as a suitable non-invasive diagnostic marker in cancer patients. For the first time in the present review, we discussed the role of miR-377 during tumor progression. It has been reported that miR-377 mainly functions as a tumor suppressor through the regulation of signaling pathways and transcription factors. This review is an important step toward introducing the miR-377 as a novel diagnostic marker as well as a therapeutic target in cancer patients.
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6
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Liao QQ, Dong QQ, Zhang H, Shu HP, Tu YC, Yao LJ. Contributions of SGK3 to transporter-related diseases. Front Cell Dev Biol 2022; 10:1007924. [PMID: 36531961 PMCID: PMC9753149 DOI: 10.3389/fcell.2022.1007924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 11/09/2022] [Indexed: 02/09/2024] Open
Abstract
Serum- and glucocorticoid-induced kinase 3 (SGK3), which is ubiquitously expressed in mammals, is regulated by estrogens and androgens. SGK3 is activated by insulin and growth factors through signaling pathways involving phosphatidylinositol-3-kinase (PI3K), 3-phosphoinositide-dependent kinase-1 (PDK-1), and mammalian target of rapamycin complex 2 (mTORC2). Activated SGK3 can activate ion channels (TRPV5/6, SOC, Kv1.3, Kv1.5, Kv7.1, BKCa, Kir2.1, Kir2.2, ENaC, Nav1.5, ClC-2, and ClC Ka), carriers and receptors (Npt2a, Npt2b, NHE3, GluR1, GluR6, SN1, EAAT1, EAAT2, EAAT4, EAAT5, SGLT1, SLC1A5, SLC6A19, SLC6A8, and NaDC1), and Na+/K+-ATPase, promoting the transportation of calcium, phosphorus, sodium, glucose, and neutral amino acids in the kidney and intestine, the absorption of potassium and neutral amino acids in the renal tubules, the transportation of glutamate and glutamine in the nervous system, and the transportation of creatine. SGK3-sensitive transporters contribute to a variety of physiological and pathophysiological processes, such as maintaining calcium and phosphorus homeostasis, hydro-salinity balance and acid-base balance, cell proliferation, muscle action potential, cardiac and neural electrophysiological disturbances, bone density, intestinal nutrition absorption, immune function, and multiple substance metabolism. These processes are related to kidney stones, hypophosphorous rickets, multiple syndromes, arrhythmia, hypertension, heart failure, epilepsy, Alzheimer's disease, amyotrophic lateral sclerosis, glaucoma, ataxia idiopathic deafness, and other diseases.
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Affiliation(s)
- Qian-Qian Liao
- Department of Nephrology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Qing-Qing Dong
- Department of Nephrology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Hui Zhang
- Department of Nephrology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Hua-Pan Shu
- Department of Nephrology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Yu-Chi Tu
- Department of Nephrology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Li-Jun Yao
- Department of Nephrology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
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7
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Yu Z, Chen J, Takagi E, Wang F, Saha B, Liu X, Joubert LM, Gleason CE, Jin M, Li C, Nowotny C, Agard D, Cheng Y, Pearce D. Interactions between mTORC2 core subunits Rictor and mSin1 dictate selective and context-dependent phosphorylation of substrate kinases SGK1 and Akt. J Biol Chem 2022; 298:102288. [PMID: 35926713 PMCID: PMC9440446 DOI: 10.1016/j.jbc.2022.102288] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 12/02/2022] Open
Abstract
Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.
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Affiliation(s)
- Zanlin Yu
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Junliang Chen
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Enzo Takagi
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Xi Liu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Lydia-Marie Joubert
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA
| | - Catherine E Gleason
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Mingliang Jin
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Chengmin Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Carlos Nowotny
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - David Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA.
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8
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Yue S, Li G, He S, Li T. The central role of mTORC1 in amino acid sensing. Cancer Res 2022; 82:2964-2974. [PMID: 35749594 DOI: 10.1158/0008-5472.can-21-4403] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/28/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth that controls cell homeostasis in response to nutrients, growth factors, and other environmental cues. Recent studies have emphasized the importance of lysosomes as a hub for nutrient sensing, especially amino acid sensing by mTORC1. This review highlights recent advances in understanding the amino acid-mTORC1 signaling axis and the role of mTORC1 in cancer.
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9
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Class III PI3K Biology. Curr Top Microbiol Immunol 2022; 436:69-93. [DOI: 10.1007/978-3-031-06566-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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10
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Pokorny D, Truebestein L, Fleming KD, Burke JE, Leonard TA. In vitro reconstitution of Sgk3 activation by phosphatidylinositol 3-phosphate. J Biol Chem 2021; 297:100919. [PMID: 34181950 PMCID: PMC8318898 DOI: 10.1016/j.jbc.2021.100919] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/09/2021] [Accepted: 06/23/2021] [Indexed: 12/19/2022] Open
Abstract
Serum- and glucocorticoid-regulated kinase 3 (Sgk3) is a serine/threonine protein kinase activated by the phospholipid phosphatidylinositol 3-phosphate (PI3P) downstream of growth factor signaling via class I phosphatidylinositol 3-kinase (PI3K) signaling and by class III PI3K/Vps34-mediated PI3P production on endosomes. Upregulation of Sgk3 activity has recently been linked to a number of human cancers; however, the precise mechanism of activation of Sgk3 is unknown. Here, we use a wide range of cell biological, biochemical, and biophysical techniques, including hydrogen-deuterium exchange mass spectrometry, to investigate the mechanism of activation of Sgk3 by PI3P. We show that Sgk3 is regulated by a combination of phosphorylation and allosteric activation. We demonstrate that binding of Sgk3 to PI3P via its regulatory phox homology (PX) domain induces large conformational changes in Sgk3 associated with its activation and that the PI3P-binding pocket of the PX domain of Sgk3 is sequestered in its inactive conformation. Finally, we reconstitute Sgk3 activation via Vps34-mediated PI3P synthesis on phosphatidylinositol liposomes in vitro. In addition to identifying the mechanism of Sgk3 activation by PI3P, our findings open up potential therapeutic avenues in allosteric inhibitor development to target Sgk3 in cancer.
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Affiliation(s)
- Daniel Pokorny
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna, Austria; Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Linda Truebestein
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna, Austria; Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas A Leonard
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna, Austria; Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria.
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11
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Simpson LM, Macartney TJ, Nardin A, Fulcher LJ, Röth S, Testa A, Maniaci C, Ciulli A, Ganley IG, Sapkota GP. Inducible Degradation of Target Proteins through a Tractable Affinity-Directed Protein Missile System. Cell Chem Biol 2020; 27:1164-1180.e5. [PMID: 32668203 PMCID: PMC7505680 DOI: 10.1016/j.chembiol.2020.06.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/19/2020] [Accepted: 06/19/2020] [Indexed: 01/01/2023]
Abstract
The affinity-directed protein missile (AdPROM) system utilizes specific polypeptide binders of intracellular proteins of interest (POIs) conjugated to an E3 ubiquitin ligase moiety to enable targeted proteolysis of the POI. However, a chemically tuneable AdPROM system is more desirable. Here, we use Halo-tag/VHL-recruiting proteolysis-targeting chimera (HaloPROTAC) technology to develop a ligand-inducible AdPROM (L-AdPROM) system. When we express an L-AdPROM construct consisting of an anti-GFP nanobody conjugated to the Halo-tag, we achieve robust degradation of GFP-tagged POIs only upon treatment of cells with the HaloPROTAC. For GFP-tagged POIs, ULK1, FAM83D, and SGK3 were knocked in with a GFP-tag using CRISPR/Cas9. By substituting the anti-GFP nanobody for a monobody that binds H- and K-RAS, we achieve robust degradation of unmodified endogenous RAS proteins only in the presence of the HaloPROTAC. Through substitution of the polypeptide binder, the highly versatile L-AdPROM system is useful for the inducible degradation of potentially any intracellular POI.
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Affiliation(s)
- Luke M Simpson
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Thomas J Macartney
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Alice Nardin
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Luke J Fulcher
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK; Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Sascha Röth
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Andrea Testa
- Division of Biological Chemistry & Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK; Amphista Therapeutics Ltd, Bo'Ness Road, Newhouse ML1 5UH, UK
| | - Chiara Maniaci
- Division of Biological Chemistry & Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK; School of Natural & Environmental Sciences, Chemistry Bedson Building, Kings Road, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
| | - Alessio Ciulli
- Division of Biological Chemistry & Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Ian G Ganley
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gopal P Sapkota
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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12
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Phosphoproteomics reveals that the hVPS34 regulated SGK3 kinase specifically phosphorylates endosomal proteins including Syntaxin-7, Syntaxin-12, RFIP4 and WDR44. Biochem J 2020; 476:3081-3107. [PMID: 31665227 PMCID: PMC6824681 DOI: 10.1042/bcj20190608] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 01/04/2023]
Abstract
The serum- and glucocorticoid-regulated kinase (SGK) isoforms contribute resistance to cancer therapies targeting the PI3K pathway. SGKs are homologous to Akt and these kinases display overlapping specificity and phosphorylate several substrates at the same residues, such as TSC2 to promote tumor growth by switching on the mTORC1 pathway. The SGK3 isoform is up-regulated in breast cancer cells treated with PI3K or Akt inhibitors and recruited and activated at endosomes, through its phox homology domain binding to PtdIns(3)P. We undertook genetic and pharmacological phosphoproteomic screens to uncover novel SGK3 substrates. We identified 40 potential novel SGK3 substrates, including four endosomal proteins STX7 (Ser126) and STX12 (Ser139), RFIP4 (Ser527) and WDR44 (Ser346) that were efficiently phosphorylated in vitro by SGK3 at the sites identified in vivo, but poorly by Akt. We demonstrate that these substrates are inefficiently phosphorylated by Akt as they possess an n + 1 residue from the phosphorylation site that is unfavorable for Akt phosphorylation. Phos-tag analysis revealed that stimulation of HEK293 cells with IGF1 to activate SGK3, promoted phosphorylation of a significant fraction of endogenous STX7 and STX12, in a manner that was blocked by knock-out of SGK3 or treatment with a pan SGK inhibitor (14H). SGK3 phosphorylation of STX12 enhanced interaction with the VAMP4/VTI1A/STX6 containing the SNARE complex and promoted plasma membrane localization. Our data reveal novel substrates for SGK3 and suggest a mechanism by which STX7 and STX12 SNARE complexes are regulated by SGK3. They reveal new biomarkers for monitoring SGK3 pathway activity.
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13
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Zheng H, Wu L, Wang X, Chen Q. Risk of Nasopharyngeal Carcinoma Associated with Single Nucleotide Polymorphisms in the MicroRNA Binding Site of SGK3. Genet Test Mol Biomarkers 2020; 24:508-519. [PMID: 32644852 DOI: 10.1089/gtmb.2019.0278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Objective: Serum/glucocorticoid regulated kinase is a serine/threonine kinase that is involved in regulating cell proliferation, apoptosis, the cell cycle, and ion channel function. The aim of this study was to analyze the relationship between single nucleotide polymorphisms (SNPs) in the microRNA (miRNA) binding site of the SGK3 gene and the risk of nasopharyngeal carcinoma (NPC). Methods: Three SGK3 loci, rs77572541, rs11994200, and rs78158330, were genotyped in 226 NPC patients and 226 healthy controls via Sanger sequencing. Quantitative real-time polymerase chain reaction was used to analyze levels of SGK3 messenger RNA (mRNA), hsa-miR-3529-5p, hsa-miR-379-5p, hsa-miR-498, hsa-miR-4320, and hsa-miR-590-3p. Western blot analysis was used to assess serum and glucocorticoid regulated kinase 3 (SGK3) protein expression. Results: SGK3 rs77572541 locus G allele carriers were 3.47 times more likely to develop NPC than carriers of the A allele (95% confidence interval [CI] = 1.98-6.09, p < 0.01). The SGK3 rs11994200 locus C allele was a major risk factor for NPC (odds ratio = 2.68, 95% CI = 1.63-4.39, p < 0.01). Similarly, carriers of the C allele of the SGK3 rs78158330 locus were 3.36 times more likely to develop NPC than those with the T allele (95% CI = 1.96-5.73, p < 0.01). The SGK3 protein was highly expressed in NPC. The SGK3 rs77572541 locus G allele is the target of hsa-miR-379-5p and hsa-miR-3529-5p, but the A allele is not. The SGK3 rs11994200 locus C allele was the target of hsa-miR-4320, and the G allele was the target of hsa-miR-498. The SGK3 rs78158330 locus T allele was the target of hsa-miR-590-3p. Hsa-miR-3529-5p, hsa-miR-379-5p, and hsa-miR-4320 were down-regulated in NPC tissues (p < 0.01), whereas hsa-miR-498 and hsa-miR-590-3p were highly expressed (p < 0.01). Conclusions: SNPs at the SGK3 loci rs77572541, rs11994200, and rs78158330 are significantly associated with the risk for NPC. These effects may be related to the influence of miRNAs on different alleles, but this needs to be verified both in vitro and in vivo.
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Affiliation(s)
- Huizhen Zheng
- Department of Otolaryngology, Wenzhou People's Hospital, Wenzhou, China
| | - Liping Wu
- Department of Otolaryngology, Huzhou Central Hospital, Huzhou, China
| | - Xiaodan Wang
- Department of Otolaryngology, The 72nd Army Hospital of the People's Liberation Army of China, Huzhou, China
| | - Qin Chen
- Department of Otolaryngology, Wenzhou Kean University, Wenzhou, China
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14
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Shorning BY, Dass MS, Smalley MJ, Pearson HB. The PI3K-AKT-mTOR Pathway and Prostate Cancer: At the Crossroads of AR, MAPK, and WNT Signaling. Int J Mol Sci 2020; 21:E4507. [PMID: 32630372 PMCID: PMC7350257 DOI: 10.3390/ijms21124507] [Citation(s) in RCA: 287] [Impact Index Per Article: 71.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/22/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022] Open
Abstract
Oncogenic activation of the phosphatidylinositol-3-kinase (PI3K), protein kinase B (PKB/AKT), and mammalian target of rapamycin (mTOR) pathway is a frequent event in prostate cancer that facilitates tumor formation, disease progression and therapeutic resistance. Recent discoveries indicate that the complex crosstalk between the PI3K-AKT-mTOR pathway and multiple interacting cell signaling cascades can further promote prostate cancer progression and influence the sensitivity of prostate cancer cells to PI3K-AKT-mTOR-targeted therapies being explored in the clinic, as well as standard treatment approaches such as androgen-deprivation therapy (ADT). However, the full extent of the PI3K-AKT-mTOR signaling network during prostate tumorigenesis, invasive progression and disease recurrence remains to be determined. In this review, we outline the emerging diversity of the genetic alterations that lead to activated PI3K-AKT-mTOR signaling in prostate cancer, and discuss new mechanistic insights into the interplay between the PI3K-AKT-mTOR pathway and several key interacting oncogenic signaling cascades that can cooperate to facilitate prostate cancer growth and drug-resistance, specifically the androgen receptor (AR), mitogen-activated protein kinase (MAPK), and WNT signaling cascades. Ultimately, deepening our understanding of the broader PI3K-AKT-mTOR signaling network is crucial to aid patient stratification for PI3K-AKT-mTOR pathway-directed therapies, and to discover new therapeutic approaches for prostate cancer that improve patient outcome.
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Affiliation(s)
| | | | | | - Helen B. Pearson
- The European Cancer Stem Cell Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, Wales, UK; (B.Y.S.); (M.S.D.); (M.J.S.)
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15
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Liu H, Paddock MN, Wang H, Murphy CJ, Geck RC, Navarro AJ, Wulf GM, Elemento O, Haucke V, Cantley LC, Toker A. The INPP4B Tumor Suppressor Modulates EGFR Trafficking and Promotes Triple-Negative Breast Cancer. Cancer Discov 2020; 10:1226-1239. [PMID: 32513774 DOI: 10.1158/2159-8290.cd-19-1262] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/22/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022]
Abstract
Inactivation of the tumor suppressor lipid phosphatase INPP4B is common in triple-negative breast cancer (TNBC). We generated a genetically engineered TNBC mouse model deficient in INPP4B. We found a dose-dependent increase in tumor incidence in INPP4B homozygous and heterozygous knockout mice compared with wild-type (WT), supporting a role for INPP4B as a tumor suppressor in TNBC. Tumors derived from INPP4B knockout mice are enriched for AKT and MEK gene signatures. Consequently, mice with INPP4B deficiency are more sensitive to PI3K or MEK inhibitors compared with WT mice. Mechanistically, we found that INPP4B deficiency increases PI(3,4)P2 levels in endocytic vesicles but not at the plasma membrane. Moreover, INPP4B loss delays degradation of EGFR and MET, while promoting recycling of receptor tyrosine kinases (RTK), thus enhancing the duration and amplitude of signaling output upon growth factor stimulation. Therefore, INPP4B inactivation in TNBC promotes tumorigenesis by modulating RTK recycling and signaling duration. SIGNIFICANCE: Inactivation of the lipid phosphatase INPP4B is frequent in TNBC. Using a genetically engineered mouse model, we show that INPP4B functions as a tumor suppressor in TNBC. INPP4B regulates RTK trafficking and degradation, such that loss of INPP4B prolongs both PI3K and ERK activation.This article is highlighted in the In This Issue feature, p. 1079.
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Affiliation(s)
- Hui Liu
- Department of Pathology and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
| | | | - Haibin Wang
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Charles J Murphy
- Meyer Cancer Center, Weill Cornell Medicine, New York, New York.,Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, New York
| | - Renee C Geck
- Department of Pathology and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Adrija J Navarro
- Department of Pathology and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Gerburg M Wulf
- Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Olivier Elemento
- Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, New York
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Lewis C Cantley
- Meyer Cancer Center, Weill Cornell Medicine, New York, New York.
| | - Alex Toker
- Department of Pathology and Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts. .,Ludwig Center at Harvard, Boston, Massachusetts
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16
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Abstract
Oocyte maturation is a process that occurs in the ovaries, where an immature oocyte resumes meiosis to attain competence for normal fertilization after ovulation/spawning. In starfish, the hormone 1-methyladenine binds to an unidentified receptor on the plasma membrane of oocytes, inducing a conformational change in the heterotrimeric GTP-binding protein α-subunit (Gα), so that the α-subunit binds GTP in exchange of GDP on the plasma membrane. The GTP-binding protein βγ-subunit (Gβγ) is released from Gα, and the released Gβγ activates phosphatidylinositol-3 kinase (PI3K), followed by the target of rapamycin kinase complex2 (TORC2) and 3-phosphoinositide-dependent protein kinase 1 (PDK1)-dependent phosphorylation of serum- and glucocorticoid-regulated kinase (SGK) of ovarian oocytes. Thereafter, SGK activates Na+/H+ exchanger (NHE) to increase the intracellular pH (pHi) from ~6.7 to ~6.9. Moreover, SGK phosphorylates Cdc25 and Myt1, thereby inducing the de-phosphorylation and activation of cyclin B–Cdk1, causing germinal vesicle breakdown (GVBD). Both pHi increase and GVBD are required for spindle assembly at metaphase I, followed by MI arrest at pHi 6.9 until spawning. Due to MI arrest or SGK-dependent pHi control, spawned oocytes can be fertilized normally
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Affiliation(s)
- Kazuyoshi Chiba
- Department of Biological Sciences, Ochanomizu University, Tokyo 112-8610, Japan
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17
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Knudsen JR, Fritzen AM, James DE, Jensen TE, Kleinert M, Richter EA. Growth Factor-Dependent and -Independent Activation of mTORC2. Trends Endocrinol Metab 2020; 31:13-24. [PMID: 31699566 DOI: 10.1016/j.tem.2019.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/19/2019] [Accepted: 09/12/2019] [Indexed: 01/03/2023]
Abstract
The target of rapamycin complex 2 (TORC2) was discovered in 2002 in budding yeast. Its mammalian counterpart, mTORC2, was first described in 2004. Soon thereafter it was demonstrated that mTORC2 directly phosphorylates Akt on Ser473, ending a long search for the elusive 'second' insulin-responsive Akt kinase. In this review we discuss key evidence pertaining to the subcellular localization of mTORC2, highlighting a spatial heterogeneity that relates to mTORC2 activation. We summarize current models for how growth factors (GFs), such as insulin, trigger mTORC2 activation, and we provide a comprehensive discussion focusing on a new exciting frontier, the molecular mechanisms underpinning GF-independent activation of mTORC2.
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Affiliation(s)
- Jonas R Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas M Fritzen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - David E James
- School of Life and Environmental Sciences and Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia; Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark; Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum Muenchen & German Center for Diabetes Research (DZD), Neuherberg, Germany.
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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18
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Sun X, Gao H, Yang Y, He M, Wu Y, Song Y, Tong Y, Rao Y. PROTACs: great opportunities for academia and industry. Signal Transduct Target Ther 2019; 4:64. [PMID: 31885879 PMCID: PMC6927964 DOI: 10.1038/s41392-019-0101-6] [Citation(s) in RCA: 339] [Impact Index Per Article: 67.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/17/2019] [Accepted: 11/21/2019] [Indexed: 02/07/2023] Open
Abstract
Although many kinds of therapies are applied in the clinic, drug-resistance is a major and unavoidable problem. Another disturbing statistic is the limited number of drug targets, which are presently only 20-25% of all protein targets that are currently being studied. Moreover, the focus of current explorations of targets are their enzymatic functions, which ignores the functions from their scaffold moiety. As a promising and appealing technology, PROteolysis TArgeting Chimeras (PROTACs) have attracted great attention both from academia and industry for finding available approaches to solve the above problems. PROTACs regulate protein function by degrading target proteins instead of inhibiting them, providing more sensitivity to drug-resistant targets and a greater chance to affect the nonenzymatic functions. PROTACs have been proven to show better selectivity compared to classic inhibitors. PROTACs can be described as a chemical knockdown approach with rapidity and reversibility, which presents new and different biology compared to other gene editing tools by avoiding misinterpretations that arise from potential genetic compensation and/or spontaneous mutations. PRTOACs have been widely explored throughout the world and have outperformed not only in cancer diseases, but also in immune disorders, viral infections and neurodegenerative diseases. Although PROTACs present a very promising and powerful approach for crossing the hurdles of present drug discovery and tool development in biology, more efforts are needed to gain to get deeper insight into the efficacy and safety of PROTACs in the clinic. More target binders and more E3 ligases applicable for developing PROTACs are waiting for exploration.
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Affiliation(s)
- Xiuyun Sun
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084 P. R. China
| | - Hongying Gao
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084 P. R. China
| | - Yiqing Yang
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084 P. R. China
| | - Ming He
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
| | - Yue Wu
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
| | - Yugang Song
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
| | - Yan Tong
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
| | - Yu Rao
- Ministry of Education (MOE) Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084 P. R. China
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, 450001 China
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19
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Abstract
![]()
SGK3
is a PX domain containing protein kinase activated at endosomes
downstream of class 1 and 3 PI3K family members by growth factors
and oncogenic mutations. SGK3 plays a key role in mediating resistance
of breast cancer cells to class 1 PI3K or Akt inhibitors, by substituting
for the loss of Akt activity and restoring proliferative pathways
such as mTORC1 signaling. It is therefore critical to develop tools
to potently target SGK3 and obstruct its role in inhibitor resistance.
Here, we describe the development of SGK3-PROTAC1, a PROTAC conjugate
of the 308-R SGK inhibitor with the VH032 VHL binding ligand, targeting
SGK3 for degradation. SGK3-PROTAC1 (0.3 μM) induced 50%
degradation of endogenous SGK3 within 2 h, with maximal 80% degradation
observed within 8 h, accompanied by a loss of phosphorylation of NDRG1,
an SGK3 substrate. SGK3-PROTAC1 did not degrade closely related SGK1
and SGK2 isoforms that are nevertheless engaged and inhibited by 308-R.
Proteomic analysis revealed that SGK3 was the only cellular protein
whose cellular levels were significantly reduced following treatment
with SGK3-PROTAC1. Low doses of SGK3-PROTAC1 (0.1–0.3 μM)
restored sensitivity of SGK3 dependent ZR-75-1 and CAMA-1 breast cancer
cells to Akt (AZD5363) and PI3K (GDC0941) inhibitors, whereas the
cis epimer analogue incapable of binding to the VHL E3 ligase had
no impact. SGK3-PROTAC1 suppressed proliferation of ZR-75-1 and CAMA-1
cancer cell lines treated with a PI3K inhibitor (GDC0941) more effectively
than could be achieved by a conventional SGK isoform inhibitor (14H).
This work underscores the benefit of the PROTAC approach in targeting
protein kinase signaling pathways with greater efficacy and selectivity
than can be achieved with conventional inhibitors. SGK3-PROTAC1 will
be an important reagent to explore the roles of the SGK3 pathway.
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20
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Hiraoka D, Hosoda E, Chiba K, Kishimoto T. SGK phosphorylates Cdc25 and Myt1 to trigger cyclin B-Cdk1 activation at the meiotic G2/M transition. J Cell Biol 2019; 218:3597-3611. [PMID: 31537708 PMCID: PMC6829662 DOI: 10.1083/jcb.201812122] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 06/03/2019] [Accepted: 07/26/2019] [Indexed: 02/06/2023] Open
Abstract
The kinase cyclin B-Cdk1 complex is a master regulator of M-phase in both mitosis and meiosis. At the G2/M transition, cyclin B-Cdk1 activation is initiated by a trigger that reverses the balance of activities between Cdc25 and Wee1/Myt1 and is further accelerated by autoregulatory loops. In somatic cell mitosis, this trigger was recently proposed to be the cyclin A-Cdk1/Plk1 axis. However, in the oocyte meiotic G2/M transition, in which hormonal stimuli induce cyclin B-Cdk1 activation, cyclin A-Cdk1 is nonessential and hence the trigger remains elusive. Here, we show that SGK directly phosphorylates Cdc25 and Myt1 to trigger cyclin B-Cdk1 activation in starfish oocytes. Upon hormonal stimulation of the meiotic G2/M transition, SGK is activated by cooperation between the Gβγ-PI3K pathway and an unidentified pathway downstream of Gβγ, called the atypical Gβγ pathway. These findings identify the trigger in oocyte meiosis and provide insights into the role and activation of SGK.
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Affiliation(s)
- Daisaku Hiraoka
- Science and Education Center, Ochanomizu University, Tokyo, Japan
| | - Enako Hosoda
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Kazuyoshi Chiba
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Takeo Kishimoto
- Science and Education Center, Ochanomizu University, Tokyo, Japan
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21
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Hosoda E, Hiraoka D, Hirohashi N, Omi S, Kishimoto T, Chiba K. SGK regulates pH increase and cyclin B-Cdk1 activation to resume meiosis in starfish ovarian oocytes. J Cell Biol 2019; 218:3612-3629. [PMID: 31537709 PMCID: PMC6829648 DOI: 10.1083/jcb.201812133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 07/19/2019] [Accepted: 08/15/2019] [Indexed: 12/31/2022] Open
Abstract
Tight regulation of intracellular pH (pHi) is essential for biological processes. Fully grown oocytes, having a large nucleus called the germinal vesicle, arrest at meiotic prophase I. Upon hormonal stimulus, oocytes resume meiosis to become fertilizable. At this time, the pHi increases via Na+/H+ exchanger activity, although the regulation and function of this change remain obscure. Here, we show that in starfish oocytes, serum- and glucocorticoid-regulated kinase (SGK) is activated via PI3K/TORC2/PDK1 signaling after hormonal stimulus and that SGK is required for this pHi increase and cyclin B-Cdk1 activation. When we clamped the pHi at 6.7, corresponding to the pHi of unstimulated ovarian oocytes, hormonal stimulation induced cyclin B-Cdk1 activation; thereafter, oocytes failed in actin-dependent chromosome transport and spindle assembly after germinal vesicle breakdown. Thus, this SGK-dependent pHi increase is likely a prerequisite for these events in ovarian oocytes. We propose a model that SGK drives meiotic resumption via concomitant regulation of the pHi and cell cycle machinery.
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Affiliation(s)
- Enako Hosoda
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Daisaku Hiraoka
- Science and Education Center, Ochanomizu University, Tokyo, Japan
| | | | - Saki Omi
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Takeo Kishimoto
- Science and Education Center, Ochanomizu University, Tokyo, Japan
| | - Kazuyoshi Chiba
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
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22
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Bilanges B, Posor Y, Vanhaesebroeck B. PI3K isoforms in cell signalling and vesicle trafficking. Nat Rev Mol Cell Biol 2019; 20:515-534. [PMID: 31110302 DOI: 10.1038/s41580-019-0129-z] [Citation(s) in RCA: 283] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PI3Ks are a family of lipid kinases that phosphorylate intracellular inositol lipids to regulate signalling and intracellular vesicular traffic. Mammals have eight isoforms of PI3K, divided into three classes. The class I PI3Ks generate 3-phosphoinositide lipids, which directly activate signal transduction pathways. In addition to being frequently genetically activated in cancer, similar mutations in class I PI3Ks have now also been found in a human non-malignant overgrowth syndrome and a primary immune disorder that predisposes to lymphoma. The class II and class III PI3Ks are regulators of membrane traffic along the endocytic route, in endosomal recycling and autophagy, with an often indirect effect on cell signalling. Here, we summarize current knowledge of the different PI3K classes and isoforms, focusing on recently uncovered biological functions and the mechanisms by which these kinases are activated. Deeper insight into the PI3K isoforms will undoubtedly continue to contribute to a better understanding of fundamental cell biological processes and, ultimately, of human disease.
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Affiliation(s)
- Benoit Bilanges
- UCL Cancer Institute, University College London, London, UK.
| | - York Posor
- UCL Cancer Institute, University College London, London, UK.
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23
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Tovell H, Testa A, Maniaci C, Zhou H, Prescott AR, Macartney T, Ciulli A, Alessi DR. Rapid and Reversible Knockdown of Endogenously Tagged Endosomal Proteins via an Optimized HaloPROTAC Degrader. ACS Chem Biol 2019; 14:882-892. [PMID: 30978004 PMCID: PMC6528276 DOI: 10.1021/acschembio.8b01016] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Inducing
post-translational protein knockdown is an important approach
to probe biology and validate drug targets. An efficient strategy
to achieve this involves expression of a protein of interest fused
to an exogenous tag, allowing tag-directed chemical degraders to mediate
protein ubiquitylation and proteasomal degradation. Here, we combine
improved HaloPROTAC degrader probes with CRISPR/Cas9 genome editing
technology to trigger rapid degradation of endogenous target proteins.
Our optimized probe, HaloPROTAC-E, a chloroalkane conjugate of high-affinity
VHL binder VH298, induced reversible degradation of two endosomally
localized proteins, SGK3 and VPS34, with a DC50 of 3–10
nM. HaloPROTAC-E induced rapid (∼50% degradation after 30 min)
and complete (Dmax of ∼95% at 48
h) depletion of Halo-tagged SGK3, blocking downstream phosphorylation
of the SGK3 substrate NDRG1. HaloPROTAC-E more potently induced greater
steady state degradation of Halo tagged endogenous VPS34 than the
previously reported HaloPROTAC3 compound. Quantitative global proteomics
revealed that HaloPROTAC-E is remarkably selective inducing only degradation
of the Halo tagged endogenous VPS34 complex (VPS34, VPS15, Beclin1,
and ATG14) and no other proteins were significantly degraded. This
study exemplifies the combination of HaloPROTACs with CRISPR/Cas9
endogenous protein tagging as a useful method to induce rapid and
reversible degradation of endogenous proteins to interrogate their
function.
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Affiliation(s)
- Hannah Tovell
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Andrea Testa
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, U.K
| | - Chiara Maniaci
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, U.K
| | - Houjiang Zhou
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Thomas Macartney
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Alessio Ciulli
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, U.K
| | - Dario R Alessi
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
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24
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Wang H, Huang F, Zhang Z, Wang P, Luo Y, Li H, Li N, Wang J, Zhou J, Wang Y, Li S. Feedback Activation of SGK3 and AKT Contributes to Rapamycin Resistance by Reactivating mTORC1/4EBP1 Axis via TSC2 in Breast Cancer. Int J Biol Sci 2019; 15:929-941. [PMID: 31182914 PMCID: PMC6535796 DOI: 10.7150/ijbs.32489] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 02/14/2019] [Indexed: 12/20/2022] Open
Abstract
The mTORC1 inhibitors, such as rapamycin and its analogs, show limited antitumor activity in clinic, reasons for which have not been clearly elucidated. Here, we undertook an effort to uncover the mechanisms underlying the limited efficacy of rapamycin, and found that the transit suppression of 4EBP1 phosphorylation led to cap-dependent translation and cell proliferation in breast cancer cells. AKT only partially contributed to 4EBP1 re-phosphorylation. By taking advantage of mass spectrometry-based phosphoproteomic analysis, we identified SGK3 as a potent kinase involved in 4EBP1 re-phosphorylation. SGK3 deletion inhibited 4EBP1 phosphorylation and cap-dependent translation. Importantly, 4EBP1 phosphorylation was positively correlated with SGK3 activity in 67 clinical breast cancer specimens. Moreover, SGK3 deletion in combination with AKT inhibition almost blocked the 4EBP1 re-phosphorylation that was induced by rapamycin and profoundly enhanced rapamycin-induced growth inhibition in vitro and in an MCF7 breast cancer mouse xenograft model in vivo. Mechanistically, the feedback activation of SGK3 by rapamycin was dependent on hVps34 and mTORC2, and reactivated mTORC1/4EBP1 axis by phosphorylating TSC2. Collectively, our study reveals a critical role of SGK3 in mediating rapamycin resistance, and provides a rationale for targeting SGK3 to improve mTOR-targeted therapies.
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Affiliation(s)
- Hongtao Wang
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China.,State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300200, China
| | - Fang Huang
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
| | - Zhe Zhang
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
| | - Peng Wang
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
| | - Yuan Luo
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Hailiang Li
- Zhuhai People's Hospital, Zhuhai Hospital Affiliated Jinan University, Zhuhai 519000, China
| | - Na Li
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
| | - Jian Wang
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
| | - Jianguang Zhou
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
| | - Yongan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Shanhu Li
- Department of Cell Engineering, Beijing Institute of Biotechnology, Beijing 100850, China
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25
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Carrera AC, Anderson R. The cell biology behind the oncogenic PIP3 lipids. J Cell Sci 2019; 132:132/1/jcs228395. [PMID: 30602575 DOI: 10.1242/jcs.228395] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 11/28/2018] [Indexed: 12/17/2022] Open
Abstract
The different mechanisms of phosphoinositide 3-kinase (PI3K) activation in cancer as well as the events that result in PI3K pathway reactivation after patient treatment with PI3K inhibitors was discussed on October 15-17th, 2018, in the medieval town of Baeza (Universidad Internacional de Andalucía, Spain) at the workshop entitled 'The cell biology behind the oncogenic PIP3 lipids'. These topics and the data presented regarding cellular functions altered by PI3K deregulation, the cooperation of PI3K/PTEN mutations with other tumor drivers, and the lessons learned for PI3K-targeted therapy, are discussed below.
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Affiliation(s)
- Ana C Carrera
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Madrid 28049, Spain
| | - Richard Anderson
- University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706-1532, USA
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26
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Ramos AR, Ghosh S, Erneux C. The impact of phosphoinositide 5-phosphatases on phosphoinositides in cell function and human disease. J Lipid Res 2018; 60:276-286. [PMID: 30194087 DOI: 10.1194/jlr.r087908] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/01/2018] [Indexed: 02/06/2023] Open
Abstract
Phosphoinositides (PIs) are recognized as major signaling molecules in many different functions of eukaryotic cells. PIs can be dephosphorylated by multiple phosphatase activities at the 5-, 4-, and 3- positions. Human PI 5-phosphatases belong to a family of 10 members. Except for inositol polyphosphate 5-phosphatase A, they all catalyze the dephosphorylation of PI(4,5)P2 and/or PI(3,4,5)P3 at the 5- position. PI 5-phosphatases thus directly control the levels of PI(3,4,5)P3 and participate in the fine-tuning regulatory mechanisms of PI(3,4)P2 and PI(4,5)P2 Second messenger functions have been demonstrated for PI(3,4)P2 in invadopodium maturation and lamellipodia formation. PI 5-phosphatases can use several substrates on isolated enzymes, and it has been challenging to establish their real substrate in vivo. PI(4,5)P2 has multiple functions in signaling, including interacting with scaffold proteins, ion channels, and cytoskeleton proteins. PI 5-phosphatase isoenzymes have been individually implicated in human diseases, such as the oculocerebrorenal syndrome of Lowe, through mechanisms that include lipid control. Oncogenic and tumor-suppressive functions of PI 5-phosphatases have also been reported in different cell contexts. The mechanisms responsible for genetic diseases and for oncogenic or tumor-suppressive functions are not fully understood. The regulation of PI 5-phosphatases is thus crucial in understanding cell functions.
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Affiliation(s)
- Ana Raquel Ramos
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Somadri Ghosh
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Christophe Erneux
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
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