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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 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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Anderson CL, Brown KA, North RJ, Walters JK, Kaska ST, Wolff MR, Kamp TJ, Ge Y, Eckhardt LL. Global Proteomic Analysis Reveals Alterations in Differentially Expressed Proteins between Cardiopathic Lamin A/C Mutations. J Proteome Res 2024. [PMID: 38718259 DOI: 10.1021/acs.jproteome.3c00853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2024]
Abstract
Lamin A/C (LMNA) is an important component of nuclear lamina. Mutations cause arrhythmia, heart failure, and sudden cardiac death. While LMNA-associated cardiomyopathy typically has an aggressive course that responds poorly to conventional heart failure therapies, there is variability in severity and age of penetrance between and even within specific mutations, which is poorly understood at the cellular level. Further, this heterogeneity has not previously been captured to mimic the heterozygous state, nor have the hundreds of clinical LMNA mutations been represented. Herein, we have overexpressed cardiopathic LMNA variants in HEK cells and utilized state-of-the-art quantitative proteomics to compare the global proteomic profiles of (1) aggregating Q353 K alone, (2) Q353 K coexpressed with WT, (3) aggregating N195 K coexpressed with WT, and (4) nonaggregating E317 K coexpressed with WT to help capture some of the heterogeneity between mutations. We analyzed each data set to obtain the differentially expressed proteins (DEPs) and applied gene ontology (GO) and KEGG pathway analyses. We found a range of 162 to 324 DEPs from over 6000 total protein IDs with differences in GO terms, KEGG pathways, and DEPs important in cardiac function, further highlighting the complexity of cardiac laminopathies. Pathways disrupted by LMNA mutations were validated with redox, autophagy, and apoptosis functional assays in both HEK 293 cells and in induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) for LMNA N195 K. These proteomic profiles expand our repertoire for mutation-specific downstream cellular effects that may become useful as druggable targets for personalized medicine approach for cardiac laminopathies.
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Affiliation(s)
- Corey L Anderson
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Kyle A Brown
- Department of Cell and Regenerative Biology, Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Ryan J North
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Janay K Walters
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Sara T Kaska
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Mathew R Wolff
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Timothy J Kamp
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Ying Ge
- Department of Cell and Regenerative Biology, Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Lee L Eckhardt
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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Wong DCP, Pan CQ, Er SY, Thivakar T, Rachel TZY, Seah SH, Chua PJ, Jiang T, Chew TW, Chaudhuri PK, Mukherjee S, Salim A, Aye TA, Koh CG, Lim CT, Tan PH, Bay BH, Ridley AJ, Low BC. The scaffold RhoGAP protein ARHGAP8/BPGAP1 synchronizes Rac and Rho signaling to facilitate cell migration. Mol Biol Cell 2023; 34:ar13. [PMID: 36598812 PMCID: PMC10011724 DOI: 10.1091/mbc.e21-03-0099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 12/14/2022] [Accepted: 12/21/2022] [Indexed: 01/05/2023] Open
Abstract
Rho GTPases regulate cell morphogenesis and motility under the tight control of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). However, the underlying mechanism(s) that coordinate their spatiotemporal activities, whether separately or together, remain unclear. We show that a prometastatic RhoGAP, ARHGAP8/BPGAP1, binds to inactive Rac1 and localizes to lamellipodia. BPGAP1 recruits the RacGEF Vav1 under epidermal growth factor (EGF) stimulation and activates Rac1, leading to polarized cell motility, spreading, invadopodium formation, and cell extravasation and promotes cancer cell migration. Importantly, BPGAP1 down-regulates local RhoA activity, which influences Rac1 binding to BPGAP1 and its subsequent activation by Vav1. Our results highlight the importance of BPGAP1 in recruiting Vav1 and Rac1 to promote Rac1 activation for cell motility. BPGAP1 also serves to control the timing of Rac1 activation with RhoA inactivation via its RhoGAP activity. BPGAP1, therefore, acts as a dual-function scaffold that recruits Vav1 to activate Rac1 while inactivating RhoA to synchronize both Rho and Rac signaling in cell motility. As epidermal growth factor receptor (EGFR), Vav1, RhoA, Rac1, and BPGAP1 are all associated with cancer metastasis, BPGAP1 could provide a crucial checkpoint for the EGFR-BPGAP1-Vav1-Rac1-RhoA signaling axis for cancer intervention.
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Affiliation(s)
| | | | - Shi Yin Er
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117558
| | - T. Thivakar
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Tan Zi Yi Rachel
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Sock Hong Seah
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Pei Jou Chua
- Department of Anatomy, Yong Loo Lin School of Medicine, National University Health System, Singapore 117594
| | - Tingting Jiang
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117558
| | - Ti Weng Chew
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | | | - Somsubhro Mukherjee
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Agus Salim
- Melbourne School of Population and Global Health and School of Mathematics and Statistics, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Thike Aye Aye
- Department of Pathology, Singapore General Hospital, Singapore 169856
| | - Cheng Gee Koh
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Chwee Teck Lim
- Mechanobiology Institute, National University of Singapore, Singapore 117411
- Department of Biomedical Engineering, National University of Singapore, Singapore 117583
| | - Puay Hoon Tan
- Department of Pathology, Singapore General Hospital, Singapore 169856
| | - Boon Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University Health System, Singapore 117594
| | - Anne J. Ridley
- School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Boon Chuan Low
- Mechanobiology Institute, National University of Singapore, Singapore 117411
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117558
- NUS College, National University of Singapore, Singapore 138593
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