Structural highlights
Function
[VILI_CHICK] Epithelial cell-specific Ca(2+)-regulated actin-modifying protein that modulates the reorganization of microvillar actin filaments. Plays a role in the actin nucleation, actin filament bundle assembly, actin filament capping and severing. Binds phosphatidylinositol 4,5-bisphosphate (PIP2) and lysophosphatidic acid (LPA); binds LPA with higher affinity than PIP2. Binding to LPA increases its phosphorylation by SRC and inhibits all actin-modifying activities. Binding to PIP2 inhibits actin-capping and -severing activities but enhances actin-bundling activity. Regulates the intestinal epithelial cell morphology, cell invasion, cell migration and apoptosis. Protects against apoptosis induced by dextran sodium sulfate (DSS) in the gastrointestinal epithelium. Appears to regulate cell death by maintaining mitochondrial integrity. Enhances hepatocyte growth factor (HGF)-induced epithelial cell motility, chemotaxis and wound repair (By similarity). Its actin-bundling activity is inhibited by tropomyosin.[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Villin 14T is the amino terminal actin monomer binding domain from the actin-severing and bundling protein villin. Its structure has been determined in solution using heteronuclear multidimensional nuclear magnetic resonance (NMR) spectroscopy (Markus MA, Nakayama T, Matsudaira P, Wagner G. 1994. Solution structure of villin 14T, a domain conserved among actin-severing proteins. Protein Science 3:70-81). An additional nuclear Overhauser effect (NOE) spectroscopy data set, acquired using improved gradient techniques, and further detailed analysis of existing data sets, produced an additional 601 NOE restraints for structure calculations. The overall fold does not change significantly with the additional NOE restraints but the definition of the structure is improved, as judged by smaller deviations among an ensemble of calculated structures that adequately satisfy the NMR restraints. Some of the side chains, especially those in the hydrophobic core of the domain, are much more defined. This improvement in the detail of the solution structure of villin 14T makes it interesting to compare the structure with the crystal structure of gelsolin segment 1, which shares 58% sequence identity with villin 14T, in an effort to gain insight into villin 14T's weaker affinity for actin monomers. Villin 14T has smaller side chains at several positions that make hydrophobic contacts with actin in the context of gelsolin segment 1. The structure is also compared with the structure of the related actin-severing domain, severin domain 2.
Refined structure of villin 14T and a detailed comparison with other actin-severing domains.,Markus MA, Matsudaira P, Wagner G Protein Sci. 1997 Jun;6(6):1197-209. PMID:9194180[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Burgess DR, Broschat KO, Hayden JM. Tropomyosin distinguishes between the two actin-binding sites of villin and affects actin-binding properties of other brush border proteins. J Cell Biol. 1987 Jan;104(1):29-40. PMID:3793760
- ↑ de Arruda MV, Bazari H, Wallek M, Matsudaira P. An actin footprint on villin. Single site substitutions in a cluster of basic residues inhibit the actin severing but not capping activity of villin. J Biol Chem. 1992 Jun 25;267(18):13079-85. PMID:1618806
- ↑ Markus MA, Matsudaira P, Wagner G. Refined structure of villin 14T and a detailed comparison with other actin-severing domains. Protein Sci. 1997 Jun;6(6):1197-209. PMID:9194180
