3tfm
Myosin X PH1N-PH2-PH1C tandem
Structural highlights
FunctionMYO10_RAT Myosins are actin-based motor molecules with ATPase activity. Unconventional myosins serve in intracellular movements. MYO10 binds to actin filaments and actin bundles and functions as a plus end-directed motor. Moves with higher velocity and takes larger steps on actin bundles than on single actin filaments (By similarity). The tail domain binds to membranous compartments containing phosphatidylinositol 3,4,5-trisphosphate or integrins, and mediates cargo transport along actin filaments. Regulates cell shape, cell spreading and cell adhesion. Stimulates the formation and elongation of filopodia. In hippocampal neurons it induces the formation of dendritic filopodia by trafficking the actin-remodeling protein VASP to the tips of filopodia, where it promotes actin elongation. Plays a role in formation of the podosome belt in osteoclasts (By similarity).[UniProtKB:Q9HD67][1] Publication Abstract from PubMedMyosin X (MyoX) is an unconventional myosin that is known to induce the formation and elongation of filopodia in many cell types. MyoX-induced filopodial induction requires the three PH domains in its tail region, although with unknown underlying molecular mechanisms. MyoX's first PH domain is split into halves by its second PH domain. We show here that the PH1(N)-PH2-PH1(C) tandem allows MyoX to bind to phosphatidylinositol (3,4,5)-triphosphate [PI(3,4,5)P(3)] with high specificity and cooperativity. We further show that PH2 is responsible for the specificity of the PI(3,4,5)P(3) interaction, whereas PH1 functions to enhance the lipid membrane-binding avidity of the tandem. The structure of the MyoX PH1(N)-PH2-PH1(C) tandem reveals that the split PH1, PH2, and the highly conserved interdomain linker sequences together form a rigid supramodule with two lipid-binding pockets positioned side by side for binding to phosphoinositide membrane bilayers with cooperativity. Finally, we demonstrate that disruption of PH2-mediated binding to PI(3,4,5)P(3) abolishes MyoX's function in inducing filopodial formation and elongation. Structural basis of the myosin X PH1N-PH2-PH1C tandem as a specific and acute cellular PI(3,4,5)P3 sensor.,Lu Q, Yu J, Yan J, Wei Z, Zhang M Mol Biol Cell. 2011 Nov;22(22):4268-78. Epub 2011 Sep 30. PMID:21965296[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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