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Shankar S, Chew TW, Chichili VPR, Low BC, Sivaraman J. Structural basis for the distinct roles of non-conserved Pro116 and conserved Tyr124 of BCH domain of yeast p50RhoGAP. Cell Mol Life Sci 2024; 81:216. [PMID: 38740643 PMCID: PMC11090974 DOI: 10.1007/s00018-024-05238-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 05/16/2024]
Abstract
p50RhoGAP is a key protein that interacts with and downregulates the small GTPase RhoA. p50RhoGAP is a multifunctional protein containing the BNIP-2 and Cdc42GAP Homology (BCH) domain that facilitates protein-protein interactions and lipid binding and the GAP domain that regulates active RhoA population. We recently solved the structure of the BCH domain from yeast p50RhoGAP (YBCH) and showed that it maintains the adjacent GAP domain in an auto-inhibited state through the β5 strand. Our previous WT YBCH structure shows that a unique kink at position 116 thought to be made by a proline residue between alpha helices α6 and α7 is essential for the formation of intertwined dimer from asymmetric monomers. Here we sought to establish the role and impact of this Pro116. However, the kink persists in the structure of P116A mutant YBCH domain, suggesting that the scaffold is not dictated by the proline residue at this position. We further identified Tyr124 (or Tyr188 in HBCH) as a conserved residue in the crucial β5 strand. Extending to the human ortholog, when substituted to acidic residues, Tyr188D or Tyr188E, we observed an increase in RhoA binding and self-dimerization, indicative of a loss of inhibition of the GAP domain by the BCH domain. These results point to distinct roles and impact of the non-conserved and conserved amino acid positions in regulating the structural and functional complexity of the BCH domain.
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Affiliation(s)
- Srihari Shankar
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Ti Weng Chew
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore
| | | | - Boon Chuan Low
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore.
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore.
- NUS College, National University of Singapore, Singapore, 138593, Singapore.
| | - J Sivaraman
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore.
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Wong DCP, Xiao J, Chew TW, Pan M, Lee CJM, Ang JW, Yow I, Thivakar T, Ackers‐Johnson M, Lee NJW, Foo RS, Kanchanawong P, Low BC. BNIP-2 Activation of Cellular Contractility Inactivates YAP for H9c2 Cardiomyoblast Differentiation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202834. [PMID: 35975420 PMCID: PMC9631078 DOI: 10.1002/advs.202202834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/17/2022] [Indexed: 06/15/2023]
Abstract
Rho GTPases and Hippo kinases are key regulators of cardiomyoblast differentiation. However, how these signaling axes are coordinated spatiotemporally remains unclear. Here, the central and multifaceted roles of the BCH domain containing protein, BNIP-2, in orchestrating the expression of two key cardiac genes (cardiac troponin T [cTnT] and cardiac myosin light chain [Myl2]) in H9c2 and human embryonic stem cell-derived cardiomyocytes are delineated. This study shows that BNIP-2 mRNA and protein expression increase with the onset of cTnT and Myl2 and promote the alignment of H9c2 cardiomyocytes. Mechanistically, BNIP-2 is required for the inactivation of YAP through YAP phosphorylation and its cytosolic retention. Turbo-ID proximity labeling corroborated by super-resolution analyses and biochemical pulldown data reveals a scaffolding role of BNIP-2 for LATS1 to phosphorylate and inactivate YAP in a process that requires BNIP-2 activation of cellular contractility. The findings identify BNIP-2 as a pivotal signaling scaffold that spatiotemporally integrates RhoA/Myosin II and LATS1/YAP mechanotransduction signaling to drive cardiomyoblast differentiation, by switching the genetic programming from YAP-dependent growth to YAP-silenced differentiation. These findings offer insights into the importance of scaffolding proteins in bridging the gap between mechanical and biochemical signals in cell growth and differentiation and the prospects in translational applications.
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Affiliation(s)
- Darren Chen Pei Wong
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
- Department of Biological SciencesNational University of SingaporeSingapore117558Singapore
| | - Jingwei Xiao
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
| | - Ti Weng Chew
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
| | - Meng Pan
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
| | - Chang Jie Mick Lee
- Genome Institute of SingaporeAgency for ScienceTechnology and ResearchSingapore138672Singapore
| | - Jing Wen Ang
- Department of Biological SciencesNational University of SingaporeSingapore117558Singapore
| | - Ivan Yow
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
| | - T. Thivakar
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
| | - Matthew Ackers‐Johnson
- Genome Institute of SingaporeAgency for ScienceTechnology and ResearchSingapore138672Singapore
- Cardiovascular Research InstituteNational University Healthcare SystemsSingapore117599Singapore
| | - Nicole Jia Wen Lee
- Department of Biological SciencesNational University of SingaporeSingapore117558Singapore
| | - Roger Sik‐Yin Foo
- Genome Institute of SingaporeAgency for ScienceTechnology and ResearchSingapore138672Singapore
- Cardiovascular Research InstituteNational University Healthcare SystemsSingapore117599Singapore
- Department of MedicineYong Loo Lin School of MedicineNational University of SingaporeSingapore117597Singapore
| | - Pakorn Kanchanawong
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
- Department of Biomedical EngineeringNational University of SingaporeSingapore117583Singapore
| | - Boon Chuan Low
- Mechanobiology Institute SingaporeNational University of SingaporeSingapore117411Singapore
- Department of Biological SciencesNational University of SingaporeSingapore117558Singapore
- NUS CollegeNational University of SingaporeSingapore138593Singapore
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Chinchole A, Lone KA, Tyagi S. MLL regulates the actin cytoskeleton and cell migration by stabilising Rho GTPases via the expression of RhoGDI1. J Cell Sci 2022; 135:jcs260042. [PMID: 36111497 PMCID: PMC7615853 DOI: 10.1242/jcs.260042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/09/2022] [Indexed: 04/26/2024] Open
Abstract
Attainment of proper cell shape and the regulation of cell migration are essential processes in the development of an organism. The mixed lineage leukemia (MLL or KMT2A) protein, a histone 3 lysine 4 (H3K4) methyltransferase, plays a critical role in cell-fate decisions during skeletal development and haematopoiesis in higher vertebrates. Rho GTPases - RhoA, Rac1 and CDC42 - are small G proteins that regulate various key cellular processes, such as actin cytoskeleton formation, the maintenance of cell shape and cell migration. Here, we report that MLL regulates the homeostasis of these small Rho GTPases. Loss of MLL resulted in an abnormal cell shape and a disrupted actin cytoskeleton, which lead to diminished cell spreading and migration. MLL depletion affected the stability and activity of Rho GTPases in a SET domain-dependent manner, but these Rho GTPases were not direct transcriptional targets of MLL. Instead, MLL regulated the transcript levels of their chaperone protein RhoGDI1 (also known as ARHGDIA). Using MDA-MB-231, a triple-negative breast cancer cell line with high RhoGDI1 expression, we show that MLL depletion or inhibition by small molecules reduces tumour progression in nude mice. Our studies highlight the central regulatory role of MLL in Rho/Rac/CDC42 signalling pathways. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Akash Chinchole
- Laboratory of Cell Cycle Regulation, Centre for DNA Fingerprinting and Diagnostics (CDFD), Uppal, Hyderabad 500039, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal 567104, India
| | - Kaisar Ahmad Lone
- Laboratory of Cell Cycle Regulation, Centre for DNA Fingerprinting and Diagnostics (CDFD), Uppal, Hyderabad 500039, India
- Graduate Studies, Regional Centre for Biotechnology, Faridabad 121001, India
| | - Shweta Tyagi
- Laboratory of Cell Cycle Regulation, Centre for DNA Fingerprinting and Diagnostics (CDFD), Uppal, Hyderabad 500039, India
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Fu MS, Pan SX, Cai XQ, Hu YX, Zhang WJ, Pan QC. Analysis of ARHGAP4 Expression With Colorectal Cancer Clinical Characteristics and Prognosis. Front Oncol 2022; 12:899837. [PMID: 35847897 PMCID: PMC9278087 DOI: 10.3389/fonc.2022.899837] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022] Open
Abstract
Background This study aims to analyze the correlation between ARHGAP4 in the expression and clinical characteristics of colorectal cancer (CRC), and the influence of ARHGAP4 expression on the prognosis of CRC, and to evaluate whether ARHGAP4 is a potential prognostic oncotarget for CRC. Methods ARHGAP4 was identified using the Gene Expression Omnibus database through weighted gene coexpression network analysis. Using the Gene Expression Profiling Interactive Analysis to perform and analyze the expression and prognosis of ARHGAP4 in CRC. The expression of AGRGAP4 and immune cells was analyzed by the Tumor IMmune Estimation Resource online database. Finally, immunohistochemistry was used to analyze the expression difference and prognosis of ARHGAP4 in CRC and adjacent normal tissues, as well as the relationship between AGRGAP4 expression and clinical features of CRC. Results We identified ARHGAP4 that is related to the recurrence of CRC from GSE97781 data. ARHGAP4 has not been reported in CRC. The high expression of ARHGAP4 in select colon adenocarcinoma indicates a poor prognosis by database analysis. In our clinical data results, ARHGAP4 is highly expressed in CRC and lowly expressed in normal tissues adjacent to cancer. Compared with the low-expression group, the high-expression group has a significantly poorer prognosis. In colon cancer, the B-cell, macrophage, neutrophil, and dendritic-cell levels are downregulated after ARHGAP4 gene knockout; the levels of CD8+ and CD4+ T cells, neutrophils, and dendritic cells are upregulated after the amplification of the ARHGAP4 gene. In addition, ARHGAP4 expression is related to N,M staging and clinical staging. Conclusion ARHGAP4 is highly expressed in CRC, and the high expression of ARHGAP4 has a poor prognosis. The expression of ARHGAP4 in CRC is related to the immune cells such as B cells, CD8+ and CD4+ T cells, macrophages, neutrophils, and dendritic cells. ARHGAP4 is correlated with N,M staging and clinical staging in CRC. ARHGAP4 may be a potential biomarker for the prognosis of CRC.
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Affiliation(s)
- Ming-sheng Fu
- Department of Gastroenterology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
- *Correspondence: Ming-sheng Fu, ; Qin-cong Pan,
| | - Shu-xian Pan
- Department of Nephrology of Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
| | - Xun-quan Cai
- Department of Gastroenterology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
| | - Yuan-xin Hu
- Department of Gastroenterology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
| | - Wei-jie Zhang
- Department of Gastroenterology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
| | - Qin-cong Pan
- Department of Gastroenterology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
- *Correspondence: Ming-sheng Fu, ; Qin-cong Pan,
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5
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Fixing the GAP: the role of RhoGAPs in cancer. Eur J Cell Biol 2022; 101:151209. [DOI: 10.1016/j.ejcb.2022.151209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 01/29/2022] [Accepted: 02/08/2022] [Indexed: 12/12/2022] Open
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Structural basis for p50RhoGAP BCH domain-mediated regulation of Rho inactivation. Proc Natl Acad Sci U S A 2021; 118:2014242118. [PMID: 34006635 DOI: 10.1073/pnas.2014242118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Spatiotemporal regulation of signaling cascades is crucial for various biological pathways, under the control of a range of scaffolding proteins. The BNIP-2 and Cdc42GAP Homology (BCH) domain is a highly conserved module that targets small GTPases and their regulators. Proteins bearing BCH domains are key for driving cell elongation, retraction, membrane protrusion, and other aspects of active morphogenesis during cell migration, myoblast differentiation, and neuritogenesis. We previously showed that the BCH domain of p50RhoGAP (ARHGAP1) sequesters RhoA from inactivation by its adjacent GAP domain; however, the underlying molecular mechanism for RhoA inactivation by p50RhoGAP remains unknown. Here, we report the crystal structure of the BCH domain of p50RhoGAP Schizosaccharomyces pombe and model the human p50RhoGAP BCH domain to understand its regulatory function using in vitro and cell line studies. We show that the BCH domain adopts an intertwined dimeric structure with asymmetric monomers and harbors a unique RhoA-binding loop and a lipid-binding pocket that anchors prenylated RhoA. Interestingly, the β5-strand of the BCH domain is involved in an intermolecular β-sheet, which is crucial for inhibition of the adjacent GAP domain. A destabilizing mutation in the β5-strand triggers the release of the GAP domain from autoinhibition. This renders p50RhoGAP active, thereby leading to RhoA inactivation and increased self-association of p50RhoGAP molecules via their BCH domains. Our results offer key insight into the concerted spatiotemporal regulation of Rho activity by BCH domain-containing proteins.
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Lee SW, Commisso C. Rac1 and EGFR cooperate to activate Pak in response to nutrient stress. Biochem Biophys Res Commun 2020; 533:437-441. [PMID: 32972756 DOI: 10.1016/j.bbrc.2020.09.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 09/11/2020] [Indexed: 12/14/2022]
Abstract
The interplay between nutrient scarcity and signal transduction circuits is an important aspect of tumorigenesis that regulates many aspects of cancer progression. Glutamine is a critical nutrient for cancer cells, as it contributes to biosynthetic reactions that sustain cancer proliferation and growth. In tumors, because nutrient utilization can often outpace supply, glutamine levels can become limiting and oncogene-mediated metabolic rewiring triggers signaling cascades that support nutrient stress survival. Recently, we identified that in pancreatic ductal adenocarcinoma (PDAC) cells, glutamine depletion can trigger p21-activated kinase (Pak) activation through EGFR signaling as a means to circumvent metabolic stress. Here, we elucidate that glutamine starvation, as well EGF stimulation, can enhance the presence of many different Pak phosphoforms, and that this activation only occurs in a subset of PDAC cells. Pak is a well-established effector of Rac1, and while Rac1 mutant variants can modulate the metabolic induction of Pak phosphorylation, Rac1 inhibition only partially attenuates Pak activation upon glutamine depletion. We decipher that in order to efficiently suppress metabolic activation of Pak, both EGFR and Rac1 signaling must be inhibited. These results provide a mechanistic understanding of how glutamine-regulated signal transduction can control Pak activation in PDAC cells.
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Affiliation(s)
- Szu-Wei Lee
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Cosimo Commisso
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
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8
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Pan M, Chew TW, Wong DCP, Xiao J, Ong HT, Chin JFL, Low BC. BNIP-2 retards breast cancer cell migration by coupling microtubule-mediated GEF-H1 and RhoA activation. SCIENCE ADVANCES 2020; 6:eaaz1534. [PMID: 32789168 PMCID: PMC7399486 DOI: 10.1126/sciadv.aaz1534] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
Microtubules display dynamic turnover during cell migration, leading to cell contractility and focal adhesion maturation regulated by Rho guanosine triphosphatase activity. This interplay between microtubules and actomyosin is mediated by guanine nucleotide exchange factor (GEF)-H1 released after microtubule depolymerization or microtubule disconnection from focal adhesions. However, how GEF-H1 activates Rho upon microtubule disassembly remains elusive. Here, we found that BNIP-2, a BCH domain-containing protein that binds both RhoA and GEF-H1 and traffics with kinesin-1 on microtubules, is important for GEF-H1-driven RhoA activation upon microtubule disassembly. Depletion of BNIP-2 in MDA-MB-231 breast cancer cells decreases RhoA activity and promotes cell migration. Upon nocodazole-induced microtubule disassembly, the interaction between BNIP-2 and GEF-H1 increases, while knockdown of BNIP-2 reduces RhoA activation and cell rounding via uncoupling RhoA-GEF-H1 interaction. Together, these findings revealed that BNIP-2 couples microtubules and focal adhesions via scaffolding GEF-H1 and RhoA, fine-tuning RhoA activity and cell migration.
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Affiliation(s)
- Meng Pan
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
| | - Ti Weng Chew
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
| | - Darren Chen Pei Wong
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
| | - Jingwei Xiao
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
| | - Hui Ting Ong
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
| | - Jasmine Fei Li Chin
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
| | - Boon Chuan Low
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore 117411, Singapore
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543, Singapore
- University Scholars Programme, 18 College Avenue East, Singapore 138593, Singapore
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Cong XX, Gao XK, Rao XS, Wen J, Liu XC, Shi YP, He MY, Shen WL, Shen Y, Ouyang H, Hu P, Low BC, Meng ZX, Ke YH, Zheng MZ, Lu LR, Liang YH, Zheng LL, Zhou YT. Rab5a activates IRS1 to coordinate IGF-AKT-mTOR signaling and myoblast differentiation during muscle regeneration. Cell Death Differ 2020; 27:2344-2362. [PMID: 32051546 DOI: 10.1038/s41418-020-0508-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 01/21/2020] [Accepted: 01/28/2020] [Indexed: 12/22/2022] Open
Abstract
Rab5 is a master regulator for endosome biogenesis and transport while its in vivo physiological function remains elusive. Here, we find that Rab5a is upregulated in several in vivo and in vitro myogenesis models. By generating myogenic Rab5a-deficient mice, we uncover the essential roles of Rab5a in regulating skeletal muscle regeneration. We further reveal that Rab5a promotes myoblast differentiation and directly interacts with insulin receptor substrate 1 (IRS1), an essential scaffold protein for propagating IGF signaling. Rab5a interacts with IRS1 in a GTP-dependent manner and this interaction is enhanced upon IGF-1 activation and myogenic differentiation. We subsequently identify that the arginine 207 and 222 of IRS1 and tyrosine 82, 89, and 90 of Rab5a are the critical amino acid residues for mediating the association. Mechanistically, Rab5a modulates IRS1 activation by coordinating the association between IRS1 and the IGF receptor (IGFR) and regulating the intracellular membrane targeting of IRS1. Both myogenesis-induced and IGF-evoked AKT-mTOR signaling are dependent on Rab5a. Myogenic deletion of Rab5a also reduces the activation of AKT-mTOR signaling during skeletal muscle regeneration. Taken together, our study uncovers the physiological function of Rab5a in regulating muscle regeneration and delineates the novel role of Rab5a as a critical switch controlling AKT-mTOR signaling by activating IRS1.
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Affiliation(s)
- Xiao Xia Cong
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Xiu Kui Gao
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Xi Sheng Rao
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jie Wen
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Xiao Ceng Liu
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yin Pu Shi
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Min Yi He
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Wei Liang Shen
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yue Shen
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Hongwei Ouyang
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,ZJU-UoE Institute, Zhejiang University School of Medicine, Hangzhou, 310058, China.,China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou, 310058, China
| | - Ping Hu
- The Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Boon Chuan Low
- Mechanobiology Institute, Department of Biological Sciences, National University of Singapore, Singapore, 117411, Singapore
| | - Zhuo Xian Meng
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yue Hai Ke
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Ming Zhu Zheng
- Department of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Lin Rong Lu
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,ZJU-UoE Institute, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Department of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yong Heng Liang
- College of Life Sciences, Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Li Ling Zheng
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Yi Ting Zhou
- Department of Biochemistry and Molecular Biology and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,ZJU-UoE Institute, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou, 310058, China.
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Hsp70 Interacts with Mitogen-Activated Protein Kinase (MAPK)-Activated Protein Kinase 2 To Regulate p38MAPK Stability and Myoblast Differentiation during Skeletal Muscle Regeneration. Mol Cell Biol 2018; 38:MCB.00211-18. [PMID: 30275345 DOI: 10.1128/mcb.00211-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 09/26/2018] [Indexed: 12/24/2022] Open
Abstract
The regenerative process of injured muscle is dependent on the fusion and differentiation of myoblasts derived from muscle stem cells. Hsp70 is important for maintaining skeletal muscle homeostasis and regeneration, but the precise cellular mechanism remains elusive. In this study, we found that Hsp70 was upregulated during myoblast differentiation. Depletion or inhibition of Hsp70/Hsc70 impaired myoblast differentiation. Importantly, overexpression of p38 mitogen-activated protein kinase α (p38MAPKα) but not AKT1 rescued the impairment of myogenic differentiation in Hsp70- or Hsc70-depleted myoblasts. Moreover, Hsp70 interacted with MK2, a substrate of p38MAPK, to regulate the stability of p38MAPK. Knockdown of Hsp70 also led to downregulation of both MK2 and p38MAPK in intact muscles and during cardiotoxin-induced muscle regeneration. Hsp70 bound MK2 to regulate MK2-p38MAPK interaction in myoblasts. We subsequently identified the essential regions required for Hsp70-MK2 interaction. Functional analyses showed that MK2 is essential for both myoblast differentiation and skeletal muscle regeneration. Taken together, our findings reveal a novel role of Hsp70 in regulating myoblast differentiation by interacting with MK2 to stabilize p38MAPK.
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11
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Zhu S, Dai J, Liu H, Cong X, Chen Y, Wu Y, Hu H, Heng BC, Ouyang HW, Zhou Y. Down-regulation of Rac GTPase-activating protein OCRL1 causes aberrant activation of Rac1 in osteoarthritis development. Arthritis Rheumatol 2015; 67:2154-63. [PMID: 25917196 DOI: 10.1002/art.39174] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 04/21/2015] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Chondrocyte hypertrophy and mineralization are considered to be important pathologic factors in osteoarthritis (OA). We previously reported that Rac1 was aberrantly activated to promote chondrocyte hypertrophy, mineralization, and expression of matrix metalloproteinase 13 and ADAMTS in OA. However, the underlying mechanism of aberrant Rac1 activation in OA is unclear. The present study was undertaken to identify the specific molecular regulator controlling Rac1 activity in OA, as well as to investigate its function in chondrocyte hypertrophy, mineralization, and OA development. METHODS Expression levels of 28 upstream regulators of Rac1 activity, including 8 GTPase-activating proteins (GAPs) and 20 guanine nucleotide exchange factors, in OA and normal cartilage were assessed by quantitative polymerase chain reaction. Chondrocytes were transduced with lentiviral vectors encoding OCRL1, GAP, non-GAP, CA-Rac1, and DN-Rac1, either alone or in combination. Alkaline phosphatase staining was used as a marker of chondrocyte hypertrophy. Rac1 activity was analyzed by pulldown assay. Finally, OA was established in mice by surgical transection of the anterior cruciate ligament and cutting of the medial meniscus. The mice were injected intraarticularly with OCRL1-encoding lentivirus, and whole joints were assessed histologically 6 weeks after surgery. RESULTS OCRL1 was abundantly expressed in normal cartilage and was the only significantly down-regulated RacGAP in OA cartilage. Overexpression of OCRL1 inhibited interleukin-1β-induced Rac1 activity, chondrocyte hypertrophy, and expression of hypertrophy-related genes. Conversely, knockdown of OCRL1 elevated Rac1 activity and promoted chondrocyte hypertrophy and mineralization. Further, OCRL1 modulated Rac1 activity via its GAP domain. Finally, intraarticular injection of OCRL1-encoding lentivirus protected against destruction and degeneration of cartilage in the mouse OA model. CONCLUSION OCRL1 acts as a RacGAP in cartilage to impede chondrocyte hypertrophy and OA development through modulating Rac1 activity. This regulatory pathway might provide potential targets for the development of new therapies for OA.
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Affiliation(s)
- Shouan Zhu
- Zhejiang University School of Medicine, Hangzhou, China
| | - Jun Dai
- Zhejiang University School of Medicine, Hangzhou, China
| | - Huanhuan Liu
- Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoxia Cong
- Zhejiang University School of Medicine, Hangzhou, China
| | - Yishan Chen
- Zhejiang University School of Medicine, Hangzhou, China
| | - Yan Wu
- Zhejiang University School of Medicine, Hangzhou, China
| | - Hu Hu
- Zhejiang University School of Medicine, Hangzhou, China
| | | | - Hong Wei Ouyang
- Zhejiang University School of Medicine and The First Affiliated Hospital, Hangzhou, China
| | - Yiting Zhou
- Zhejiang University School of Medicine, Hangzhou, China
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12
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Yi P, Chew LL, Zhang Z, Ren H, Wang F, Cong X, Zheng L, Luo Y, Ouyang H, Low BC, Zhou YT. KIF5B transports BNIP-2 to regulate p38 mitogen-activated protein kinase activation and myoblast differentiation. Mol Biol Cell 2014; 26:29-42. [PMID: 25378581 PMCID: PMC4279227 DOI: 10.1091/mbc.e14-03-0797] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cdo bridges scaffold proteins BNIP-2 and JLP to activate p38MAPK during myoblast differentiation. KIF5B is a novel interacting partner of BNIP-2 and promotes myogenic differentiation. KIF5B-dependent transport of BNIP-2 is essential for its promyogenic effects. The Cdo-p38MAPK (p38 mitogen-activated protein kinase) signaling pathway plays important roles in regulating skeletal myogenesis. During myogenic differentiation, the cell surface receptor Cdo bridges scaffold proteins BNIP-2 and JLP and activates p38MAPK, but the spatial-temporal regulation of this process is largely unknown. We here report that KIF5B, the heavy chain of kinesin-1 motor, is a novel interacting partner of BNIP-2. Coimmunoprecipitation and far-Western study revealed that BNIP-2 directly interacted with the motor and tail domains of KIF5B via its BCH domain. By using a range of organelle markers and live microscopy, we determined the endosomal localization of BNIP-2 and revealed the microtubule-dependent anterograde transport of BNIP-2 in C2C12 cells. The anterograde transport of BNIP-2 was disrupted by a dominant-negative mutant of KIF5B. In addition, knockdown of KIF5B causes aberrant aggregation of BNIP-2, confirming that KIF5B is critical for the anterograde transport of BNIP-2 in cells. Gain- and loss-of-function experiments further showed that KIF5B modulates p38MAPK activity and in turn promotes myogenic differentiation. Of importance, the KIF5B-dependent anterograde transport of BNIP-2 is critical for its promyogenic effects. Our data reveal a novel role of KIF5B in the spatial regulation of Cdo–BNIP-2–p38MAPK signaling and disclose a previously unappreciated linkage between the intracellular transporting system and myogenesis regulation.
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Affiliation(s)
- Peng Yi
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Li Li Chew
- Department of Biological Sciences and Mechanobiology Institute, National University of Singapore, 117411 Singapore
| | - Ziwang Zhang
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Hao Ren
- Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Feiya Wang
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Xiaoxia Cong
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Liling Zheng
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and
| | - Yan Luo
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and
| | - Hongwei Ouyang
- Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Boon Chuan Low
- Department of Biological Sciences and Mechanobiology Institute, National University of Singapore, 117411 Singapore
| | - Yi Ting Zhou
- Center for Stem Cell and Tissue Engineering, Department of Biochemistry and Molecular Biology, and Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
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13
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Jaiswal M, Dvorsky R, Amin E, Risse SL, Fansa EK, Zhang SC, Taha MS, Gauhar AR, Nakhaei-Rad S, Kordes C, Koessmeier KT, Cirstea IC, Olayioye MA, Häussinger D, Ahmadian MR. Functional cross-talk between ras and rho pathways: a Ras-specific GTPase-activating protein (p120RasGAP) competitively inhibits the RhoGAP activity of deleted in liver cancer (DLC) tumor suppressor by masking the catalytic arginine finger. J Biol Chem 2014; 289:6839-6849. [PMID: 24443565 DOI: 10.1074/jbc.m113.527655] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The three deleted in liver cancer genes (DLC1-3) encode Rho-specific GTPase-activating proteins (RhoGAPs). Their expression is frequently silenced in a variety of cancers. The RhoGAP activity, which is required for full DLC-dependent tumor suppressor activity, can be inhibited by the Src homology 3 (SH3) domain of a Ras-specific GAP (p120RasGAP). Here, we comprehensively investigated the molecular mechanism underlying cross-talk between two distinct regulators of small GTP-binding proteins using structural and biochemical methods. We demonstrate that only the SH3 domain of p120 selectively inhibits the RhoGAP activity of all three DLC isoforms as compared with a large set of other representative SH3 or RhoGAP proteins. Structural and mutational analyses provide new insights into a putative interaction mode of the p120 SH3 domain with the DLC1 RhoGAP domain that is atypical and does not follow the classical PXXP-directed interaction. Hence, p120 associates with the DLC1 RhoGAP domain by targeting the catalytic arginine finger and thus by competitively and very potently inhibiting RhoGAP activity. The novel findings of this study shed light on the molecular mechanisms underlying the DLC inhibitory effects of p120 and suggest a functional cross-talk between Ras and Rho proteins at the level of regulatory proteins.
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Affiliation(s)
- Mamta Jaiswal
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Radovan Dvorsky
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Ehsan Amin
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Sarah L Risse
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Eyad K Fansa
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Si-Cai Zhang
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Mohamed S Taha
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Aziz R Gauhar
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Saeideh Nakhaei-Rad
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Claus Kordes
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf
| | - Katja T Koessmeier
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Ion C Cirstea
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf; Leibniz Institute for Age Research, 07745 Jena
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf
| | - Mohammad R Ahmadian
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf.
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14
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Abstract
Small GTPases use GDP/GTP alternation to actuate a variety of functional switches that are pivotal for cell dynamics. The GTPase switch is turned on by GEFs, which stimulate dissociation of the tightly bound GDP, and turned off by GAPs, which accelerate the intrinsically sluggish hydrolysis of GTP. For Ras, Rho, and Rab GTPases, this switch incorporates a membrane/cytosol alternation regulated by GDIs and GDI-like proteins. The structures and core mechanisms of representative members of small GTPase regulators from most families have now been elucidated, illuminating their general traits combined with scores of unique features. Recent studies reveal that small GTPase regulators have themselves unexpectedly sophisticated regulatory mechanisms, by which they process cellular signals and build up specific cell responses. These mechanisms include multilayered autoinhibition with stepwise release, feedback loops mediated by the activated GTPase, feed-forward signaling flow between regulators and effectors, and a phosphorylation code for RhoGDIs. The flipside of these highly integrated functions is that they make small GTPase regulators susceptible to biochemical abnormalities that are directly correlated with diseases, notably a striking number of missense mutations in congenital diseases, and susceptible to bacterial mimics of GEFs, GAPs, and GDIs that take command of small GTPases in infections. This review presents an overview of the current knowledge of these many facets of small GTPase regulation.
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Affiliation(s)
- Jacqueline Cherfils
- Laboratoire d’Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Centre deRecherche de Gif, Gif-sur-Yvette, France
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15
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Bmcc1s interacts with the phosphate-activated glutaminase in the brain. Biochimie 2012; 95:799-807. [PMID: 23246912 DOI: 10.1016/j.biochi.2012.11.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 11/26/2012] [Indexed: 11/24/2022]
Abstract
Bmcc1s, a brain-enriched short isoform of the BCH-domain containing molecule Bmcc1, has recently been shown to interact with the microtubule-associated protein MAP6 and to regulate cell morphology. Here we identified kidney-type glutaminase (KGA), the mitochondrial enzyme responsible for the conversion of glutamine to glutamate in neurons, as a novel partner of Bmcc1s. Co-immunoprecipitation experiments confirmed that Bmcc1s and KGA form a physiological complex in the brain, whereas binding and modeling studies showed that they interact with each other. Overexpression of Bmcc1s in mouse primary cortical neurons impaired proper mitochondrial targeting of KGA leading to its accumulation within the cytoplasm. Thus, Bmcc1s may control the trafficking of KGA to the mitochondria.
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16
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Ravichandran A, Low BC. SmgGDS antagonizes BPGAP1-induced Ras/ERK activation and neuritogenesis in PC12 cell differentiation. Mol Biol Cell 2012; 24:145-56. [PMID: 23155002 PMCID: PMC3541961 DOI: 10.1091/mbc.e12-04-0300] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BPGAP1 controls morphogenesis, migration, and ERK signaling by the concerted action of its multiple domains. Its BCH domain targets K-Ras and induces robust ERK activation and neuronal differentiation in a process antagonized by SmgGDS. The results highlight unique cross-talk of two regulators of GTPases in Ras/ERK signaling and differentiation. BPGAP1 is a Rho GTPase-activating protein (RhoGAP) that regulates cell morphogenesis, cell migration, and ERK signaling by the concerted action of its proline-rich region (PRR), RhoGAP domain, and the BNIP-2 and Cdc42GAP homology (BCH) domain. Although multiple cellular targets for the PRR and RhoGAP have been identified, and their functions delineated, the mechanism by which the BCH domain regulates functions of BPGAP1 remains unclear. Here we show that its BCH domain induced robust ERK activation leading to PC12 cell differentiation by targeting specifically to K-Ras. Such stimulatory effect was inhibited, however, by both dominant-negative mutants of Mek2 (Mek2-K101A) and K-Ras (K-Ras-S17N) and also by the small G-protein GDP dissociation stimulator (SmgGDS). Consequently SmgGDS knockdown released this inhibition and resulted in a superinduction of K-Ras activation and PC12 differentiation mediated by BCH domain. These results demonstrate the versatility of the BCH domain of BPGAP1 in regulating ERK signaling by involving K-Ras and SmgGDS and support the unique role of BPGAP1 as a dual regulator for Ras and Rho signaling in cell morphogenesis and differentiation.
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Affiliation(s)
- Aarthi Ravichandran
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117543, Republic of Singapore
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17
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Modified SH2 domain to phototrap and identify phosphotyrosine proteins from subcellular sites within cells. Proc Natl Acad Sci U S A 2012; 109:E2929-38. [PMID: 23027962 DOI: 10.1073/pnas.1207358109] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Spatial regulation of tyrosine phosphorylation is important for many aspects of cell biology. However, phosphotyrosine accounts for less than 1% of all phosphorylated substrates, and it is typically a very transient event in vivo. These factors complicate the identification of key tyrosine kinase substrates, especially in the context of their extraordinary spatial organization. Here, we describe an approach to identify tyrosine kinase substrates based on their subcellular distribution from within cells. This method uses an unnatural amino acid-modified Src homology 2 (SH2) domain that is expressed within cells and can covalently trap phosphotyrosine proteins on exposure to light. This SH2 domain-based photoprobe was targeted to cellular structures, such as the actin cytoskeleton, mitochondria, and cellular membranes, to capture tyrosine kinase substrates unique to each cellular region. We demonstrate that RhoA, one of the proteins associated with actin, can be phosphorylated on two tyrosine residues within the switch regions, suggesting that phosphorylation of these residues might modulate RhoA signaling to the actin cytoskeleton. We conclude that expression of SH2 domains within cellular compartments that are capable of covalent phototrapping can reveal the spatial organization of tyrosine kinase substrates that are likely to be important for the regulation of subcellular structures.
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18
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FIP3-endosome-dependent formation of the secondary ingression mediates ESCRT-III recruitment during cytokinesis. Nat Cell Biol 2012; 14:1068-78. [PMID: 23000966 DOI: 10.1038/ncb2577] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 08/09/2012] [Indexed: 12/19/2022]
Abstract
The final cytokinesis event involves severing of the connecting intercellular bridge (ICB) between daughter cells. FIP3-positive recycling endosomes (FIP3 endosomes) and ESCRT complexes have been implicated in mediating the final stages of cytokinesis. Here we analyse the spatiotemporal dynamics of the actin cytoskeleton, FIP3-endosome fusion and ESCRT-III localization during cytokinesis to show that the ICB narrows by a FIP3-endosome-mediated secondary ingression, whereas the ESCRT-III complex is needed only for the last scission step of cytokinesis. We characterize the role of FIP3 endosomes during cytokinesis to demonstrate that FIP3 endosomes deliver SCAMP2/3 and p50RhoGAP to the ICB during late telophase, proteins required for the formation of the secondary ingression. We also show that the FIP3-endosome-induced secondary ingression is required for the recruitment of the ESCRT-III complex to the abscission site. Finally, we characterize a FIP3-endosome-dependent regulation of the ICB cortical actin network through the delivery of p50RhoGAP. These results provide a framework for the coordinated efforts of actin, FIP3 endosomes and the ESCRTs to regulate cytokinesis and abscission.
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19
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Pan CQ, Sudol M, Sheetz M, Low BC. Modularity and functional plasticity of scaffold proteins as p(l)acemakers in cell signaling. Cell Signal 2012; 24:2143-65. [PMID: 22743133 DOI: 10.1016/j.cellsig.2012.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 05/22/2012] [Accepted: 06/16/2012] [Indexed: 01/14/2023]
Abstract
Cells coordinate and integrate various functional modules that control their dynamics, intracellular trafficking, metabolism and gene expression. Such capacity is mediated by specific scaffold proteins that tether multiple components of signaling pathways at plasma membrane, Golgi apparatus, mitochondria, endoplasmic reticulum, nucleus and in more specialized subcellular structures such as focal adhesions, cell-cell junctions, endosomes, vesicles and synapses. Scaffold proteins act as "pacemakers" as well as "placemakers" that regulate the temporal, spatial and kinetic aspects of protein complex assembly by modulating the local concentrations, proximity, subcellular dispositions and biochemical properties of the target proteins through the intricate use of their modular protein domains. These regulatory mechanisms allow them to gate the specificity, integration and crosstalk of different signaling modules. In addition to acting as physical platforms for protein assembly, many professional scaffold proteins can also directly modify the properties of their targets while they themselves can be regulated by post-translational modifications and/or mechanical forces. Furthermore, multiple scaffold proteins can form alliances of higher-order regulatory networks. Here, we highlight the emerging themes of scaffold proteins by analyzing their common and distinctive mechanisms of action and regulation, which underlie their functional plasticity in cell signaling. Understanding these mechanisms in the context of space, time and force should have ramifications for human physiology and for developing new therapeutic approaches to control pathological states and diseases.
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Affiliation(s)
- Catherine Qiurong Pan
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Republic of Singapore.
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20
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Pan CQ, Low BC. Functional plasticity of the BNIP-2 and Cdc42GAP Homology (BCH) domain in cell signaling and cell dynamics. FEBS Lett 2012; 586:2674-91. [DOI: 10.1016/j.febslet.2012.04.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 04/16/2012] [Accepted: 04/16/2012] [Indexed: 10/28/2022]
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21
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Arama J, Boulay AC, Bosc C, Delphin C, Loew D, Rostaing P, Amigou E, Ezan P, Wingertsmann L, Guillaud L, Andrieux A, Giaume C, Cohen-Salmon M. Bmcc1s, a novel brain-isoform of Bmcc1, affects cell morphology by regulating MAP6/STOP functions. PLoS One 2012; 7:e35488. [PMID: 22523599 PMCID: PMC3327665 DOI: 10.1371/journal.pone.0035488] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 03/16/2012] [Indexed: 12/21/2022] Open
Abstract
The BCH (BNIP2 and Cdc42GAP Homology) domain-containing protein Bmcc1/Prune2 is highly enriched in the brain and is involved in the regulation of cytoskeleton dynamics and cell survival. However, the molecular mechanisms accounting for these functions are poorly defined. Here, we have identified Bmcc1s, a novel isoform of Bmcc1 predominantly expressed in the mouse brain. In primary cultures of astrocytes and neurons, Bmcc1s localized on intermediate filaments and microtubules and interacted directly with MAP6/STOP, a microtubule-binding protein responsible for microtubule cold stability. Bmcc1s overexpression inhibited MAP6-induced microtubule cold stability by displacing MAP6 away from microtubules. It also resulted in the formation of membrane protrusions for which MAP6 was a necessary cofactor of Bmcc1s. This study identifies Bmcc1s as a new MAP6 interacting protein able to modulate MAP6-induced microtubule cold stability. Moreover, it illustrates a novel mechanism by which Bmcc1 regulates cell morphology.
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Affiliation(s)
- Jessica Arama
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France
- University Pierre et Marie Curie, ED, N°158, Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France
| | - Anne-Cécile Boulay
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France
- University Pierre et Marie Curie, ED, N°158, Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France
| | - Christophe Bosc
- Equipe Physiopathologie du Cytosquelette, Institut National de la Santé et de la Recherche Médicale U836, Institut des Neurosciences, Université Joseph Fourier, Faculté de Médecine, Domaine de la Merci, La Tronche, France
| | - Christian Delphin
- Equipe Physiopathologie du Cytosquelette, Institut National de la Santé et de la Recherche Médicale U836, Institut des Neurosciences, Université Joseph Fourier, Faculté de Médecine, Domaine de la Merci, La Tronche, France
| | - Damarys Loew
- Institut Curie, Laboratory of Proteomic Mass Spectrometry, Paris, France
| | - Philippe Rostaing
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Institut National de la Santé et de la Recherche Médicale U1024, Paris, France
| | - Edwige Amigou
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France
- University Pierre et Marie Curie, ED, N°158, Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France
| | - Pascal Ezan
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France
- University Pierre et Marie Curie, ED, N°158, Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France
| | - Laure Wingertsmann
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Institut National de la Santé et de la Recherche Médicale U1024, Paris, France
| | - Laurent Guillaud
- Cell and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Annie Andrieux
- Equipe Physiopathologie du Cytosquelette, Institut National de la Santé et de la Recherche Médicale U836, Institut des Neurosciences, Université Joseph Fourier, Faculté de Médecine, Domaine de la Merci, La Tronche, France
| | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France
- University Pierre et Marie Curie, ED, N°158, Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France
| | - Martine Cohen-Salmon
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France
- University Pierre et Marie Curie, ED, N°158, Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France
- * E-mail:
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22
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Gupta AB, Wee LE, Zhou YT, Hortsch M, Low BC. Cross-species analyses identify the BNIP-2 and Cdc42GAP homology (BCH) domain as a distinct functional subclass of the CRAL_TRIO/Sec14 superfamily. PLoS One 2012; 7:e33863. [PMID: 22479462 PMCID: PMC3313917 DOI: 10.1371/journal.pone.0033863] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 02/18/2012] [Indexed: 11/19/2022] Open
Abstract
The CRAL_TRIO protein domain, which is unique to the Sec14 protein superfamily, binds to a diverse set of small lipophilic ligands. Similar domains are found in a range of different proteins including neurofibromatosis type-1, a Ras GTPase-activating Protein (RasGAP) and Rho guanine nucleotide exchange factors (RhoGEFs). Proteins containing this structural protein domain exhibit a low sequence similarity and ligand specificity while maintaining an overall characteristic three-dimensional structure. We have previously demonstrated that the BNIP-2 and Cdc42GAP Homology (BCH) protein domain, which shares a low sequence homology with the CRAL_TRIO domain, can serve as a regulatory scaffold that binds to Rho, RhoGEFs and RhoGAPs to control various cell signalling processes. In this work, we investigate 175 BCH domain-containing proteins from a wide range of different organisms. A phylogenetic analysis with ∼100 CRAL_TRIO and similar domains from eight representative species indicates a clear distinction of BCH-containing proteins as a novel subclass within the CRAL_TRIO/Sec14 superfamily. BCH-containing proteins contain a hallmark sequence motif R(R/K)h(R/K)(R/K)NL(R/K)xhhhhHPs (‘h’ is large and hydrophobic residue and ‘s’ is small and weekly polar residue) and can be further subdivided into three unique subtypes associated with BNIP-2-N, macro- and RhoGAP-type protein domains. A previously unknown group of genes encoding ‘BCH-only’ domains is also identified in plants and arthropod species. Based on an analysis of their gene-structure and their protein domain context we hypothesize that BCH domain-containing genes evolved through gene duplication, intron insertions and domain swapping events. Furthermore, we explore the point of divergence between BCH and CRAL-TRIO proteins in relation to their ability to bind small GTPases, GAPs and GEFs and lipid ligands. Our study suggests a need for a more extensive analysis of previously uncharacterized BCH, ‘BCH-like’ and CRAL_TRIO-containing proteins and their significance in regulating signaling events involving small GTPases.
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Affiliation(s)
- Anjali Bansal Gupta
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Liang En Wee
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Yi Ting Zhou
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Michael Hortsch
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Boon Chuan Low
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
- * E-mail:
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