1
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Mousavy Gharavy SN, Owen BM, Millership SJ, Chabosseau P, Pizza G, Martinez-Sanchez A, Tasoez E, Georgiadou E, Hu M, Fine NHF, Jacobson DA, Dickerson MT, Idevall-Hagren O, Montoya A, Kramer H, Mehta Z, Withers DJ, Ninov N, Gadue PJ, Cardenas-Diaz FL, Cruciani-Guglielmacci C, Magnan C, Ibberson M, Leclerc I, Voz M, Rutter GA. Sexually dimorphic roles for the type 2 diabetes-associated C2cd4b gene in murine glucose homeostasis. Diabetologia 2021; 64:850-864. [PMID: 33492421 PMCID: PMC7829492 DOI: 10.1007/s00125-020-05350-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/28/2020] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Variants close to the VPS13C/C2CD4A/C2CD4B locus are associated with altered risk of type 2 diabetes in genome-wide association studies. While previous functional work has suggested roles for VPS13C and C2CD4A in disease development, none has explored the role of C2CD4B. METHODS CRISPR/Cas9-induced global C2cd4b-knockout mice and zebrafish larvae with c2cd4a deletion were used to study the role of this gene in glucose homeostasis. C2 calcium dependent domain containing protein (C2CD)4A and C2CD4B constructs tagged with FLAG or green fluorescent protein were generated to investigate subcellular dynamics using confocal or near-field microscopy and to identify interacting partners by mass spectrometry. RESULTS Systemic inactivation of C2cd4b in mice led to marked, but highly sexually dimorphic changes in body weight and glucose homeostasis. Female C2cd4b mice displayed unchanged body weight compared with control littermates, but abnormal glucose tolerance (AUC, p = 0.01) and defective in vivo, but not in vitro, insulin secretion (p = 0.02). This was associated with a marked decrease in follicle-stimulating hormone levels as compared with wild-type (WT) littermates (p = 0.003). In sharp contrast, male C2cd4b null mice displayed essentially normal glucose tolerance but an increase in body weight (p < 0.001) and fasting blood glucose (p = 0.003) after maintenance on a high-fat and -sucrose diet vs WT littermates. No metabolic disturbances were observed after global inactivation of C2cd4a in mice, or in pancreatic beta cell function at larval stages in C2cd4a null zebrafish. Fasting blood glucose levels were also unaltered in adult C2cd4a-null fish. C2CD4B and C2CD4A were partially localised to the plasma membrane, with the latter under the control of intracellular Ca2+. Binding partners for both included secretory-granule-localised PTPRN2/phogrin. CONCLUSIONS/INTERPRETATION Our studies suggest that C2cd4b may act centrally in the pituitary to influence sex-dependent circuits that control pancreatic beta cell function and glucose tolerance in rodents. However, the absence of sexual dimorphism in the impact of diabetes risk variants argues for additional roles for C2CD4A or VPS13C in the control of glucose homeostasis in humans. DATA AVAILABILITY The datasets generated and/or analysed during the current study are available in the Biorxiv repository ( www.biorxiv.org/content/10.1101/2020.05.18.099200v1 ). RNA-Seq (GSE152576) and proteomics (PXD021597) data have been deposited to GEO ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE152576 ) and ProteomeXchange ( www.ebi.ac.uk/pride/archive/projects/PXD021597 ) repositories, respectively.
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Affiliation(s)
- S Neda Mousavy Gharavy
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Bryn M Owen
- Section of Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Steven J Millership
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Pauline Chabosseau
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Grazia Pizza
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Aida Martinez-Sanchez
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Emirhan Tasoez
- DFG-Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
| | - Eleni Georgiadou
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Ming Hu
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Nicholas H F Fine
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics Vanderbilt University, Nashville, TN, USA
| | - Matthew T Dickerson
- Department of Molecular Physiology and Biophysics Vanderbilt University, Nashville, TN, USA
| | | | - Alex Montoya
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
| | - Holger Kramer
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
| | - Zenobia Mehta
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Nikolay Ninov
- DFG-Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
| | - Paul J Gadue
- Children's Hospital of Philadelphia, CTRB, Philadelphia, PA, USA
| | | | | | - Christophe Magnan
- Regulation of Glycemia by Central Nervous System, BFA, UMR 8251, CNRS Université de Paris, Paris, France
| | - Mark Ibberson
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Isabelle Leclerc
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Marianne Voz
- Laboratory of Zebrafish Development and Disease Models, University of Liège (ULg), Liège, Belgium
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
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2
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The structure and function of protein kinase C-related kinases (PRKs). Biochem Soc Trans 2021; 49:217-235. [PMID: 33522581 PMCID: PMC7925014 DOI: 10.1042/bst20200466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/29/2020] [Accepted: 01/07/2021] [Indexed: 11/17/2022]
Abstract
The protein kinase C-related kinase (PRK) family of serine/threonine kinases, PRK1, PRK2 and PRK3, are effectors for the Rho family small G proteins. An array of studies have linked these kinases to multiple signalling pathways and physiological roles, but while PRK1 is relatively well-characterized, the entire PRK family remains understudied. Here, we provide a holistic overview of the structure and function of PRKs and describe the molecular events that govern activation and autoregulation of catalytic activity, including phosphorylation, protein interactions and lipid binding. We begin with a structural description of the regulatory and catalytic domains, which facilitates the understanding of their regulation in molecular detail. We then examine their diverse physiological roles in cytoskeletal reorganization, cell adhesion, chromatin remodelling, androgen receptor signalling, cell cycle regulation, the immune response, glucose metabolism and development, highlighting isoform redundancy but also isoform specificity. Finally, we consider the involvement of PRKs in pathologies, including cancer, heart disease and bacterial infections. The abundance of PRK-driven pathologies suggests that these enzymes will be good therapeutic targets and we briefly report some of the progress to date.
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3
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Scott JL, Frick CT, Johnson KA, Liu H, Yong SS, Varney AG, Wiest O, Stahelin RV. Molecular Analysis of Membrane Targeting by the C2 Domain of the E3 Ubiquitin Ligase Smurf1. Biomolecules 2020; 10:biom10020229. [PMID: 32033048 PMCID: PMC7072158 DOI: 10.3390/biom10020229] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 12/18/2022] Open
Abstract
SMAD ubiquitination regulatory factor 1 (Smurf1) is a Nedd4 family E3 ubiquitin ligase that regulates cell motility, polarity and TGFβ signaling. Smurf1 contains an N-terminal protein kinase C conserved 2 (C2) domain that targets cell membranes and is required for interactions with membrane-localized substrates such as RhoA. Here, we investigated the lipid-binding mechanism of Smurf1 C2, revealing a general affinity for anionic membranes in addition to a selective affinity for phosphoinositides (PIPs). We found that Smurf1 C2 localizes not only to the plasma membrane but also to negatively charged intracellular sites, acting as an anionic charge sensor and selective PIP-binding domain. Site-directed mutagenesis combined with docking/molecular dynamics simulations revealed that the Smurf1 C2 domain loop region primarily interacts with PIPs and cell membranes, as opposed to the β-surface cationic patch employed by other C2 domains. By depleting PIPs from the inner leaflet of the plasma membrane, we found that PIP binding is necessary for plasma membrane localization. Finally, we used a Smurf1 cellular ubiquitination assay to show that the amount of ubiquitin at the plasma membrane interface depends on the lipid-binding properties of Smurf1. This study shows the mechanism by which Smurf1 C2 targets membrane-based substrates and reveals a novel interaction for non-calcium-dependent C2 domains and membrane lipids.
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Affiliation(s)
- Jordan L. Scott
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Cary T. Frick
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Kristen A. Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Haining Liu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Sylvia S. Yong
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Allyson G. Varney
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; (J.L.S.); (C.T.F.); (K.A.J.); (H.L.); (S.S.Y.); (A.G.V.); (O.W.)
| | - Robert V. Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
- Correspondence: ; Tel.: +1-765-494-4152
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4
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Javadi A, Deevi RK, Evergren E, Blondel-Tepaz E, Baillie GS, Scott MGH, Campbell FC. PTEN controls glandular morphogenesis through a juxtamembrane β-Arrestin1/ARHGAP21 scaffolding complex. eLife 2017; 6:e24578. [PMID: 28749339 PMCID: PMC5576923 DOI: 10.7554/elife.24578] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 07/24/2017] [Indexed: 01/01/2023] Open
Abstract
PTEN controls three-dimensional (3D) glandular morphogenesis by coupling juxtamembrane signaling to mitotic spindle machinery. While molecular mechanisms remain unclear, PTEN interacts through its C2 membrane-binding domain with the scaffold protein β-Arrestin1. Because β-Arrestin1 binds and suppresses the Cdc42 GTPase-activating protein ARHGAP21, we hypothesize that PTEN controls Cdc42 -dependent morphogenic processes through a β-Arrestin1-ARHGAP21 complex. Here, we show that PTEN knockdown (KD) impairs β-Arrestin1 membrane localization, β-Arrestin1-ARHGAP21 interactions, Cdc42 activation, mitotic spindle orientation and 3D glandular morphogenesis. Effects of PTEN deficiency were phenocopied by β-Arrestin1 KD or inhibition of β-Arrestin1-ARHGAP21 interactions. Conversely, silencing of ARHGAP21 enhanced Cdc42 activation and rescued aberrant morphogenic processes of PTEN-deficient cultures. Expression of the PTEN C2 domain mimicked effects of full-length PTEN but a membrane-binding defective mutant of the C2 domain abrogated these properties. Our results show that PTEN controls multicellular assembly through a membrane-associated regulatory protein complex composed of β-Arrestin1, ARHGAP21 and Cdc42.
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Affiliation(s)
- Arman Javadi
- Centre for Cancer Research and Cell BiologyQueen’s University of BelfastBelfastUnited Kingdom
| | - Ravi K Deevi
- Centre for Cancer Research and Cell BiologyQueen’s University of BelfastBelfastUnited Kingdom
| | - Emma Evergren
- Centre for Cancer Research and Cell BiologyQueen’s University of BelfastBelfastUnited Kingdom
| | - Elodie Blondel-Tepaz
- Inserm, U1016, Institut CochinParisFrance
- CNRS, UMR8104ParisFrance
- Univ. Paris Descartes, Sorbonne Paris CitéParisFrance
| | - George S Baillie
- Institute of Cardiovascular and Medical Science, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowScotland
| | - Mark GH Scott
- Inserm, U1016, Institut CochinParisFrance
- CNRS, UMR8104ParisFrance
- Univ. Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Frederick C Campbell
- Centre for Cancer Research and Cell BiologyQueen’s University of BelfastBelfastUnited Kingdom
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5
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Alwarawrah M, Wereszczynski J. Investigation of the Effect of Bilayer Composition on PKCα-C2 Domain Docking Using Molecular Dynamics Simulations. J Phys Chem B 2016; 121:78-88. [PMID: 27997184 DOI: 10.1021/acs.jpcb.6b10188] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The protein kinase Cα (PKCα) enzyme is a member of a broad family of serine/threonine kinases, which are involved in varied cellular signaling pathways. The initial step of PKCα activation involves the C2 subunit docking with the cell membrane, which is followed by interactions of the C1 domains with diacylglycerol (DAG) in the membrane. Notably, the molecular mechanisms of these interactions remain poorly understood, especially what effects, if any, DAG may have on the initial C2 docking. To further understand this process, we have performed a series of conventional molecular dynamics simulations to systematically investigate the interaction between PKCα-C2 domains and lipid bilayers with different compositions to examine the effects of POPS, PIP2, and 1-palmitoyl-2-oleoyl-sn-glycerol (POG) on domain docking. Our results show that the PKCα-C2 domain does not interact with the bilayer surface in the absence of POPS and PIP2. In contrast, the inclusion of POPS and PIP2 to the bilayer resulted in strong domain docking in both perpendicular and parallel orientations, whereas the further inclusion of POG resulted in only parallel domain docking. In addition, lysine residues in the C2 domain formed hydrogen bonds with PIP2 molecule bilayers containing POG. These effects were further explored with umbrella sampling calculations to estimate the free energy of domain docking to the lipid bilayer in the presence of one or two PIP2 molecules. The results show that the binding of one or two PIP2 molecules is thermodynamically favorable, although stronger in bilayers lacking POG. However, in POG-containing bilayers, the binding mode of the C2 domain appears to be more flexible, which may have implications for activation of full-length PKCα. Together, our results shed new insights into the process of C2 bilayer binding and suggest new mechanisms for the roles of different phospholipids in the activation process of PKCα.
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Affiliation(s)
- Mohammad Alwarawrah
- Department of Physics and Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology , Chicago 60616, Illinois, United States
| | - Jeff Wereszczynski
- Department of Physics and Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology , Chicago 60616, Illinois, United States
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6
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Ku BM, Yune YP, Lee ES, Hah YS, Park JY, Jeong JY, Lee DH, Cho GJ, Choi WS, Kang SS. PKCη Regulates the TGFβ3-induced Chondevrepogenic Differentiation of Human Mesenchymal Stem Cell. Dev Reprod 2015; 17:299-309. [PMID: 25949145 PMCID: PMC4382954 DOI: 10.12717/dr.2013.17.4.299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 11/07/2013] [Accepted: 11/11/2013] [Indexed: 11/17/2022]
Abstract
Transforming growth factor (TGF) family is well known to induce the chondevrepogenic differentiation of mesenchymal stem cells (MSC). However, the precise signal transduction pathways and underlying factors are not well known. Thus the present study aims to evaluate the possible role of C2 domain in the chondevrepogenic differentiation of human mesenchymal stem cells. To this end, 145 C2 domains in the adenovirus were individually transfected to hMSC, and morphological changes were examined. Among 145 C2 domains, C2 domain of protein kinase C eta (PKCη) was selected as a possible chondevrepogenic differentiation factor for hMSC. To confirm this possibility, we treated TGFβ3, a well known chondevrepogenic differentiation factor of hMSC, and examined the increased-expression of glycosaminoglycan (GAG), collagen type II (COL II) as well as PKCη using PT-PCR, immunocytochemistry and Western blot analysis. To further evaluation of C2 domain of PKCη, we examined morphological changes, expressions of GAG and COL II after transfection of PKCη -C2 domain in hMSC. Overexpression of PKCη-C2 domain induced morphological change and increased GAG and COL II expressions. The present results demonstrate that PKCη involves in the TGF-β3-induced chondevrepogenic differentiation of hMSC, and C2 domain of PKCη has important role in this process.
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Affiliation(s)
- Bo Mi Ku
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Young Phil Yune
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Eun Shin Lee
- Department of Rehabilitation Medicine, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Young-Sool Hah
- Clinical Research Institute, Gyeongsang National University Hospital, Jinju 660-702, Republic of Korea
| | - Jae Yong Park
- Dept. of Physiology, School of Medicine, Gyeongsang National University, Jinju 660-751, Republic of Korea
| | - Joo Yeon Jeong
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Dong Hoon Lee
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Gyeong Jae Cho
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Wan Sung Choi
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
| | - Sang Soo Kang
- Department of Anatomy & Neurobiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 660-290, Republic of Korea
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7
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PTEN phosphatase-independent maintenance of glandular morphology in a predictive colorectal cancer model system. Neoplasia 2014; 15:1218-30. [PMID: 24348097 DOI: 10.1593/neo.121516] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/08/2013] [Accepted: 10/11/2013] [Indexed: 02/06/2023] Open
Abstract
Organotypic models may provide mechanistic insight into colorectal cancer (CRC) morphology. Three-dimensional (3D) colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN) coupling of cell division cycle 42 (cdc42) to atypical protein kinase C (aPKC). This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM) orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3) were ineffective. The isolated PTEN C2 domain (C2) accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na(+)/H(+) exchanger regulatory factor-1 (NHERF-1) in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system.
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8
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Assessing the subcellular distribution of oncogenic phosphoinositide 3-kinase using microinjection into live cells. Biosci Rep 2014; 34:BSR20130133. [PMID: 27919038 PMCID: PMC3985441 DOI: 10.1042/bsr20130133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/18/2014] [Accepted: 03/04/2014] [Indexed: 02/07/2023] Open
Abstract
Oncogenic mutations in PIK3CA lead to an increase in intrinsic phosphoinositide kinase activity, but it is thought that increased access of PI3Kα (phosphoinositide 3-kinase α) to its PM (plasma membrane) localized substrate is also required for increased levels of downstream PIP3/Akt [phosphoinositide-3,4,5-trisphosphate/also called PKB (protein kinase B)] signalling. We have studied the subcellular localization of wild-type and the two most common oncogenic mutants of PI3Kα in cells maintained in growth media, and starved or stimulated cells using a novel method in which PI3Kα is pre-formed as a 1:1 p110α:p85α complex in vitro then introduced into live cells by microinjection. Oncogenic E545K and H1047R mutants did not constitutively interact with membrane lipids in vitro or in cells maintained in 10% (v/v) FBS. Following stimulation of RTKs (receptor tyrosine kinases), microinjected PI3Kα was recruited to the PM, but oncogenic forms of PI3Kα were not recruited to the PM to a greater extent and did not reside at the PM longer than the wild-type PI3Kα. Instead, the E545K mutant specifically bound activated Cdc42 in vitro and microinjection of E545K was associated with the formation of cellular protrusions, providing some preliminary evidence that changes in protein–protein interactions may play a role in the oncogenicity of the E545K mutant in addition to the well-known changes in lipid kinase activity. Oncogenic forms of PI3Kα (phosphoinositide 3-kinase α) microinjected into live cells are not recruited to the PM (plasma membrane) to a greater extent, and do not reside at the PM longer, than wild-type PI3Kα.
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9
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Ziemba BP, Li J, Landgraf KE, Knight JD, Voth GA, Falke JJ. Single-molecule studies reveal a hidden key step in the activation mechanism of membrane-bound protein kinase C-α. Biochemistry 2014; 53:1697-713. [PMID: 24559055 PMCID: PMC3971957 DOI: 10.1021/bi4016082] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
![]()
Protein
kinase C-α (PKCα) is a member of the conventional
family of protein kinase C isoforms (cPKCs) that regulate diverse
cellular signaling pathways, share a common activation mechanism,
and are linked to multiple pathologies. The cPKC domain structure
is modular, consisting of an N-terminal pseudosubstrate peptide, two
inhibitory domains (C1A and C1B), a targeting domain (C2), and a kinase
domain. Mature, cytoplasmic cPKCs are inactive until they are switched
on by a multistep activation reaction that occurs largely on the plasma
membrane surface. Often, this activation begins with a cytoplasmic
Ca2+ signal that triggers C2 domain targeting to the plasma
membrane where it binds phosphatidylserine (PS) and phosphatidylinositol
4,5-bisphosphate (PIP2). Subsequently, the appearance of
the signaling lipid diacylglycerol (DAG) activates the membrane-bound
enzyme by recruiting the inhibitory pseudosubstrate and one or both
C1 domains away from the kinase domain. To further investigate this
mechanism, this study has utilized single-molecule total internal
reflection fluorescence microscopy (TIRFM) to quantitate the binding
and lateral diffusion of full-length PKCα and fragments missing
specific domain(s) on supported lipid bilayers. Lipid binding events,
and events during which additional protein is inserted into the bilayer,
were detected by their effects on the equilibrium bound particle density
and the two-dimensional diffusion rate. In addition to the previously
proposed activation steps, the findings reveal a major, undescribed,
kinase-inactive intermediate. On bilayers containing PS or PS and
PIP2, full-length PKCα first docks to the membrane
via its C2 domain, and then its C1A domain embeds itself in the bilayer
even before DAG appears. The resulting pre-DAG intermediate with membrane-bound
C1A and C2 domains is the predominant state of PKCα while it
awaits the DAG signal. The newly detected, membrane-embedded C1A domain
of this pre-DAG intermediate confers multiple useful features, including
enhanced membrane affinity and longer bound state lifetime. The findings
also identify the key molecular step in kinase activation: because
C1A is already membrane-embedded in the kinase off state, recruitment
of C1B to the bilayer by DAG or phorbol ester is the key regulatory
event that stabilizes the kinase on state. More broadly, this study
illustrates the power of single-molecule methods in elucidating the
activation mechanisms and hidden regulatory states of membrane-bound
signaling proteins.
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Affiliation(s)
- Brian P Ziemba
- Department of Chemistry and Biochemistry and Molecular Biophysics Program, University of Colorado , Boulder, Colorado 80309-0596, United States
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10
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Morales KA, Yang Y, Long Z, Li P, Taylor AB, Hart PJ, Igumenova TI. Cd2+ as a Ca2+ surrogate in protein-membrane interactions: isostructural but not isofunctional. J Am Chem Soc 2013; 135:12980-3. [PMID: 23937054 PMCID: PMC4749353 DOI: 10.1021/ja406958k] [Citation(s) in RCA: 9] [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
Due to its favorable spectroscopic properties, Cd(2+) is frequently used as a probe of Ca(2+) sites in proteins. We investigate the ability of Cd(2+) to act as a structural and functional surrogate of Ca(2+) in protein-membrane interactions. C2 domain from protein kinase Cα (C2α) was chosen as a paradigm for the Ca(2+)-dependent phosphatidylserine-binding peripheral membrane domains. We identified the Cd(2+)-binding sites of C2α using NMR spectroscopy, determined the 1.6 Å crystal structure of Cd(2+)-bound C2α, and characterized metal-ion-dependent interactions between C2α and phospholipid membranes using fluorescence spectroscopy and ultracentrifugation experiments. We show that Cd(2+) forms a tight complex with the membrane-binding loops of C2α but is unable to support its membrane-binding function. This is in sharp contrast with Pb(2+), which is almost as effective as Ca(2+) in driving the C2α-membrane association process. Our results provide the first direct evidence for the specific role of divalent metal ions in mediating protein-membrane interactions, have important implications for metal substitution studies in proteins, and illustrate the potential diversity of functional responses caused by toxic metal ions.
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Affiliation(s)
- Krystal A. Morales
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Yuan Yang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Zheng Long
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Alexander B. Taylor
- Department of Biochemistry and the X-ray Crystallography Core Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
| | - P. John Hart
- Department of Biochemistry and the X-ray Crystallography Core Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
| | - Tatyana I. Igumenova
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
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Morales KA, Igumenova TI. Synergistic effect of Pb(2+) and phosphatidylinositol 4,5-bisphosphate on C2 domain-membrane interactions. Biochemistry 2012; 51:3349-60. [PMID: 22475207 DOI: 10.1021/bi201850h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ca(2+)-responsive C2 domains are peripheral membrane modules that target their host proteins to anionic membranes upon binding Ca(2+) ions. Several C2 domain-containing proteins, such as protein kinase C isoenzymes (PKCs), have been identified as molecular targets of Pb(2+), a known environmental toxin. We demonstrated previously that the C2 domain from PKCα (C2α) binds Pb(2+) with high affinity and undergoes membrane insertion in the Pb(2+)-complexed form. The objective of this work was to determine the effect of phosphatidylinositol 4,5-bisphosphate (PIP(2)) on the C2α-Pb(2+) interactions. Using nuclear magnetic resonance (NMR) experiments, we show that Pb(2+) and PIP(2) synergistically enhance each other's affinity for C2α. Moreover, the affinity of C2α for PIP(2) increases upon progressive saturation of the metal-binding sites. Combining the NMR data with the results of protein-to-membrane Förster resonance energy transfer and vesicle sedimentation experiments, we demonstrate that PIP(2) can influence two aspects of C2α-Pb(2+)-membrane interactions: the affinity of C2α for Pb(2+) and the association of Pb(2+) with the anionic sites on the membrane. Both factors may contribute to the toxic effect of Pb(2+) resulting from the aberrant modulation of PKCα activity. Finally, we propose a mechanism for Pb(2+) outcompeting Ca(2+) from membrane-bound C2α.
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Affiliation(s)
- Krystal A Morales
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843-2128, USA
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12
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Scott JL, Musselman CA, Adu-Gyamfi E, Kutateladze TG, Stahelin RV. Emerging methodologies to investigate lipid-protein interactions. Integr Biol (Camb) 2012; 4:247-58. [PMID: 22327461 DOI: 10.1039/c2ib00143h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cellular membranes are composed of hundreds of different lipids, ion channels, receptors and scaffolding complexes that act as signalling and trafficking platforms for processes fundamental to life. Cellular signalling and membrane trafficking are often regulated by peripheral proteins, which reversibly interact with lipid molecules in highly regulated spatial and temporal fashions. In most cases, one or more modular lipid-binding domain(s) mediate recruitment of peripheral proteins to specific cellular membranes. These domains, of which more than 10 have been identified since 1989, harbour structurally selective lipid-binding sites. Traditional in vitro and in vivo studies have elucidated how these domains coordinate their cognate lipids and thus how the parent proteins associate with membranes. Cellular activities of peripheral proteins and subsequent physiological processes depend upon lipid binding affinities and selectivity. Thus, the development of novel sensitive and quantitative tools is essential in furthering our understanding of the function and regulation of these proteins. As this field expands into new areas such as computational biology, cellular lipid mapping, single molecule imaging, and lipidomics, there is an urgent need to integrate technologies to detail the molecular architecture and mechanisms of lipid signalling. This review surveys emerging cellular and in vitro approaches for studying protein-lipid interactions and provides perspective on how integration of methodologies directs the future development of the field.
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Affiliation(s)
- Jordan L Scott
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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Huang Q, Szebenyi DME. Structural basis for the interaction between the growth factor-binding protein GRB10 and the E3 ubiquitin ligase NEDD4. J Biol Chem 2010; 285:42130-9. [PMID: 20980250 PMCID: PMC3009938 DOI: 10.1074/jbc.m110.143412] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 10/11/2010] [Indexed: 01/28/2023] Open
Abstract
In addition to inhibiting insulin receptor and IGF1R kinase activity by directly binding to the receptors, GRB10 can also negatively regulate insulin and IGF1 signaling by mediating insulin receptor and IGF1R degradation through ubiquitination. It has been shown that GRB10 can interact with the C2 domain of the E3 ubiquitin ligase NEDD4 through its Src homology 2 (SH2) domain. Therefore, GRB10 might act as a connector, bringing NEDD4 close to IGF1R to facilitate the ubiquitination of IGF1R by NEDD4. This is the first case in which it has been found that an SH2 domain could colocalize a ubiquitin ligase and its substrate. Here we report the crystal structure of the NEDD4 C2-GRB10 SH2 complex at 2.0 Å. The structure shows that there are three interaction interfaces between NEDD4 C2 and GRB10 SH2. The main interface centers on an antiparallel β-sheet composed of the F β-strand of GRB10 SH2 and the C β-strand of NEDD4 C2. NEDD4 C2 binds at nonclassical sites on the SH2 domain surface, far from the classical phosphotyrosine-binding pocket. Hence, this interaction is phosphotyrosine-independent, and GRB10 SH2 can bind the C2 domain of NEDD4 and the kinase domain of IGF1R simultaneously. Based on these results, a model of how NEDD4 interacts with IGF1R through GRB10 has been proposed. This report provides further evidence that SH2 domains can participate in important signaling interactions beyond the classical recognition of phosphotyrosine.
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Affiliation(s)
- Qingqiu Huang
- MacCHESS, Cornell University, Ithaca, New York 14853, USA.
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Xue M, Craig TK, Shin OH, Li L, Brautigam CA, Tomchick DR, Südhof TC, Rosenmund C, Rizo J. Structural and mutational analysis of functional differentiation between synaptotagmins-1 and -7. PLoS One 2010; 5. [PMID: 20824061 PMCID: PMC2932738 DOI: 10.1371/journal.pone.0012544] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 08/09/2010] [Indexed: 01/16/2023] Open
Abstract
Synaptotagmins are known to mediate diverse forms of Ca2+-triggered exocytosis through their C2 domains, but the principles underlying functional differentiation among them are unclear. Synaptotagmin-1 functions as a Ca2+ sensor in neurotransmitter release at central nervous system synapses, but synaptotagmin-7 does not, and yet both isoforms act as Ca2+ sensors in chromaffin cells. To shed light into this apparent paradox, we have performed rescue experiments in neurons from synaptotagmin-1 knockout mice using a chimera that contains the synaptotagmin-1 sequence with its C2B domain replaced by the synaptotagmin-7 C2B domain (Syt1/7). Rescue was not achieved either with the WT Syt1/7 chimera or with nine mutants where residues that are distinct in synaptotagmin-7 were restored to those present in synaptotagmin-1. To investigate whether these results arise because of unique conformational features of the synaptotagmin-7 C2B domain, we determined its crystal structure at 1.44 Å resolution. The synaptotagmin-7 C2B domain structure is very similar to that of the synaptotagmin-1 C2B domain and contains three Ca2+-binding sites. Two of the Ca2+-binding sites of the synaptotagmin-7 C2B domain are also present in the synaptotagmin-1 C2B domain and have analogous ligands to those determined for the latter by NMR spectroscopy, suggesting that a discrepancy observed in a crystal structure of the synaptotagmin-1 C2B domain arose from crystal contacts. Overall, our results suggest that functional differentiation in synaptotagmins arises in part from subtle sequence changes that yield dramatic functional differences.
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Affiliation(s)
- Mingshan Xue
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
| | - Timothy K. Craig
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Ok-Ho Shin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Liyi Li
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Chad A. Brautigam
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Diana R. Tomchick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Thomas C. Südhof
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, California, United States of America
- Howard Hughes Medical Institute, Stanford University, Palo Alto, California, United States of America
| | - Christian Rosenmund
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Neuroscience Research Center, Charite-Universitätsmedizin Berlin, Berlin, Germany
- Cluster of Excellence NeuroCure, Charite-Universitätsmedizin Berlin, Berlin, Germany
- * E-mail: (CR); (JR)
| | - Josep Rizo
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail: (CR); (JR)
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