|
General Comment |
Interacts with LATS1/2. Hippo signaling. Zyx was identified as a novel component of the Hippo pathway through
an RNAi-based genetic screen (Rauskolb et al., 2011). Like Jub, Zyx positively regulates Yki activity in flies, and acts
upstream of Wts. ////Zyxin, a regulator of actin filament assembly, targets the mitotic apparatus by interacting with h-warts/LATS1 tumor suppressor. Hirota T et al. The mitotic apparatus plays a pivotal role in dividing cells to ensure each daughter cell receives a full set of chromosomes and complement of cytoplasm during mitosis. A human homologue of the Drosophila warts tumor suppressor, h-warts/LATS1, is an evolutionarily conserved serine/threonine kinase and a dynamic component of the mitotic apparatus. We have identified an interaction of h-warts/LATS1 with zyxin, a regulator of actin filament assembly. Zyxin is a component of focal adhesion, however, during mitosis a fraction of cytoplasmic-dispersed zyxin becomes associated with h-warts/LATS1 on the mitotic apparatus. We found that zyxin is phosphorylated specifically during mitosis, most likely by Cdc2 kinase, and that the phosphorylation regulates association with h-warts/LATS1. Furthermore, microinjection of truncated h-warts/LATS1 protein, including the zyxin-binding portion, interfered with localization of zyxin to mitotic apparatus, and the duration of mitosis of these injected cells was significantly longer than that of control cells. These findings suggest that h-warts/LATS1 and zyxin play a crucial role in controlling mitosis progression by forming a regulatory complex on mitotic apparatus.
NCBI Summary:
Focal adhesions are actin-rich structures that enable cells to adhere to the extracellular matrix and at which protein complexes involved in signal transduction assemble. Zyxin is a zinc-binding phosphoprotein that concentrates at focal adhesions and along the actin cytoskeleton. Zyxin has an N-terminal proline-rich domain and three LIM domains in its C-terminal half. The proline-rich domain may interact with SH3 domains of proteins involved in signal transduction pathways while the LIM domains are likely involved in protein-protein binding. Zyxin may function as a messenger in the signal transduction pathway that mediates adhesion-stimulated changes in gene expression and may modulate the cytoskeletal organization of actin bundles. Alternative splicing results in multiple transcript variants that encode the same isoform. [provided by RefSeq, Jul 2008]
|
|
Mutations |
1 mutations
Species: mouse
Mutation name: None
type: null mutation
fertility: fertile
Comment: Targeted disruption of the murine zyxin gene. Hoffman LM 2002 et al.
Zyxin is an evolutionarily conserved protein that is concentrated at sites of cell adhesion, where it associates with members of the Enabled (Ena)/vasodilator-stimulated phosphoprotein (VASP) family of cytoskeletal regulators and is postulated to play a role in cytoskeletal dynamics and signaling. Zyxin transcripts are detected throughout murine embryonic development, and the protein is widely expressed in adults. Here we used a reverse genetic approach to examine the consequences of loss of zyxin function in the mouse. Mice that lack zyxin function are viable and fertile and display no obvious histological abnormalities in any of the organs examined. Because zyxin contributes to the localization of Ena/VASP family members at certain subcellular locations, we carefully examined the zyxin(-/-) mice for evidence of defects that have been observed when Ena/VASP proteins are compromised in the mouse. Specifically, we evaluated blood platelet function, nervous system development, and skin architecture but did not detect any defects in these systems. Zyxin is the founding member of a family of proteins that also includes the lipoma preferred partner (LPP) and thyroid receptor-interacting protein 6 (TRIP6). These zyxin family members display patterns of expression that significantly overlap that of zyxin. Western blot analysis indicates that there is no detectable upregulation of either LPP or TRIP6 expression in tissues derived from zyxin-null mice. Because zyxin family members may have overlapping functions, a comprehensive understanding of the role of these proteins in the mouse will require the generation of compound mutations in which multiple zyxin family members are simultaneously compromised.
/////////////////////////
|