Villin1 Rabbit Polyclonal Antibody (ER1901-31)

UNIPROT #

P09327

PROTEIN NAME

Villin1

SYNONYMS

D2S1471 antibody;OTTHUMP00000164145 antibody;VIL antibody;VIL1 antibody;VILI_HUMAN antibody;Villin 1 antibody;Villin-1 antibody;Villin1 antibody

SEQUENCE SIMILARITIES

Belongs to the villin/gelsolin family.

TISSUE SPECIFICITY

Specifically expressed in epithelial cells. Major component of microvilli of intestinal epithelial cells and kidney proximal tubule cells. Expressed in canalicular microvilli of hepatocytes (at protein level).

POST-TRANSLATIONAL MODIFICATION

Tyrosine phosphorylation is induced by epidermal growth factor (EGF) and stimulates cell migration (By similarity). Phosphorylated on tyrosine residues by SRC. The unphosphorylated form increases the initial rate of actin-nucleating activity, whereas the tyrosine-phosphorylated form inhibits actin-nucleating activity, enhances actin-bundling activity and enhances actin-severing activity by reducing high Ca(2+) requirements. The tyrosine-phosphorylated form does not regulate actin-capping activity. Tyrosine phosphorylation is essential for cell migration: tyrosine phosphorylation sites in the N-terminus half regulate actin reorganization and cell morphology, whereas tyrosine phosphorylation sites in the C-terminus half regulate cell migration via interaction with PLCG1.

SUBCELLULAR LOCATION

Cytoplasm, cytoskeleton, Cell projection.

FUNCTION

Villin-1 is believed to function in the bundling, nucleation, capping and severing of actin filaments. In vertebrates, villin proteins help to support the microfilaments of the microvilli of the brush border. However, knockout mice appear to show ultra-structurally normal microvilli reminding us that the function of villin is not definitively known; it may play a role in cell plasticity through F-actin severing. The six-repeat villin core is responsible for Ca2+ actin severing while the headpiece is responsible for actin crosslinking and bundling (Ca independent). Villin is postulated to be the controlling protein for Ca2+ induced actin severing in the brush border. Ca2+ inhibits proteolytic cleavage of the domains of the 6 N-terminal core which inhibits actin severing. In normal mice raising Ca2+ levels induces the severing of actin by villin, whereas in villin knockout mice this activity does not occur in response to heightened Ca2+ levels.[8] In the presence of low concentrations of Ca2+ the villin headpiece functions to bundle actin filaments whereas in the presence of high Ca2+ concentrations the N-terminal caps and severs these filaments. The association of PIP2 with villin inhibits the actin capping and severing action and increases actin binding at the headpiece region, possibly through structural changes in the protein. PIP2 increases actin bundling not only by decreasing the severing action of villin but also through dissociating capping proteins, releasing actin monomers from sequestering proteins and stimulating actin nucleation and cross linking