This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2loz
From Proteopedia
The novel binding mode of DLC1 and Tensin2 PTB domain
Structural highlights
FunctionTENS2_HUMAN Tyrosine-protein phosphatase which regulates cell motility, proliferation and muscle-response to insulin (PubMed:15817639, PubMed:23401856). Phosphatase activity is mediated by binding to phosphatidylinositol-3,4,5-triphosphate (PtdIns(3,4,5)P3) via the SH2 domain (PubMed:30092354). In muscles and under catabolic conditions, dephosphorylates IRS1 leading to its degradation and muscle atrophy (PubMed:23401856, PubMed:30092354). Negatively regulates PI3K-AKT pathway activation (PubMed:15817639, PubMed:23401856, PubMed:30092354). Dephosphorylates nephrin NPHS1 in podocytes which regulates activity of the mTORC1 complex (PubMed:28955049). Under normal glucose conditions, NPHS1 outcompetes IRS1 for binding to phosphatidylinositol 3-kinase (PI3K) which balances mTORC1 activity but high glucose conditions lead to up-regulation of TNS2, increased NPHS1 dephosphorylation and activation of mTORC1, contributing to podocyte hypertrophy and proteinuria (PubMed:28955049). Required for correct podocyte morphology, podocyte-glomerular basement membrane interaction and integrity of the glomerular filtration barrier (By similarity). Enhances RHOA activation in the presence of DLC1 (PubMed:26427649). Plays a role in promoting DLC1-dependent remodeling of the extracellular matrix (PubMed:20069572).[UniProtKB:Q8CGB6][1] [2] [3] [4] [5] [6] Publication Abstract from PubMedThe protein deleted in liver cancer 1 (DLC1) interacts with the tensin family of focal adhesion proteins to play a role as a tumor suppressor in a wide spectrum of human cancers. This interaction has been proven to be crucial to the oncogenic inhibitory capacity and focal adhesion localization of DLC1. The phosphotyrosine binding (PTB) domain of tensin2 predominantly interacts with a novel site on DLC1, not the canonical NPXY motif. In this study, we characterized this interaction biochemically and determined the complex structure of tensin2 PTB domain with DLC1 peptide by NMR spectroscopy. Our HADDOCK-derived complex structure model elucidates the molecular mechanism by which tensin2 PTB domain recognizes DLC1 peptide and reveals a PTB-peptide binding mode that is unique in that peptide occupies the binding site opposite to the canonical NPXY motif interaction site with the peptide utilizing a non-canonical binding motif to bind in an extended conformation and that the N-terminal helix, which is unique to some Shc- and Dab-like PTB domains, is required for binding. Mutations of crucial residues defined for the PTB-DLC1 interaction affected the co-localization of DLC1 and tensin2 in cells and abolished DLC1-mediated growth suppression of hepatocellular carcinoma cells. This tensin2 PTB-DLC1 peptide complex with a novel binding mode extends the versatile binding repertoire of the PTB domains in mediating diverse cellular signaling pathways as well as provides a molecular and structural basis for better understanding the tumor-suppressive activity of DLC1 and tensin2. Solution structure of the phosphotyrosine binding (PTB) domain of human tensin2 protein in complex with deleted in liver cancer 1 (DLC1) peptide reveals a novel peptide binding mode.,Chen L, Liu C, Ko FC, Xu N, Ng IO, Yam JW, Zhu G J Biol Chem. 2012 Jul 27;287(31):26104-14. doi: 10.1074/jbc.M112.360206. Epub, 2012 May 29. PMID:22645138[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||
Categories: Homo sapiens | Large Structures | Chen L | Liu C | Zhu G
