7yv9
From Proteopedia
Cryo-EM structure of full-length Myosin Va in the autoinhibited state
Structural highlights
FunctionCALM1_MOUSE Calmodulin acts as part of a calcium signal transduction pathway by mediating the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Calcium-binding is required for the activation of calmodulin. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases, such as myosin light-chain kinases and calmodulin-dependent protein kinase type II (CaMK2), and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis. Is a regulator of voltage-dependent L-type calcium channels. Mediates calcium-dependent inactivation of CACNA1C. Positively regulates calcium-activated potassium channel activity of KCNN2. Forms a potassium channel complex with KCNQ1 and regulates electrophysiological activity of the channel via calcium-binding. Acts as a sensor to modulate the endoplasmic reticulum contacts with other organelles mediated by VMP1:ATP2A2.[UniProtKB:P0DP23] Publication Abstract from PubMedAs the prototype of unconventional myosin motor family, myosin Va (MyoVa) transport cellular cargos along actin filaments in diverse cellular processes. The off-duty MyoVa adopts a closed and autoinhibited state, which can be relieved by cargo binding. The molecular mechanisms governing the autoinhibition and activation of MyoVa remain unclear. Here, we report the cryo-electron microscopy structure of the two full-length, closed MyoVa heavy chains in complex with 12 calmodulin light chains at 4.78-A resolution. The MyoVa adopts a triangular structure with multiple intra- and interpolypeptide chain interactions in establishing the closed state with cargo binding and adenosine triphosphatase activity inhibited. Structural, biochemical, and cellular analyses uncover an asymmetric autoinhibition mechanism, in which the cargo-binding sites in the two MyoVa heavy chains are differently protected. Thus, specific and efficient MyoVa activation requires coincident binding of multiple cargo adaptors, revealing an intricate and elegant activity regulation of the motor in response to cargos. Autoinhibition and activation mechanisms revealed by the triangular-shaped structure of myosin Va.,Niu F, Liu Y, Sun K, Xu S, Dong J, Yu C, Yan K, Wei Z Sci Adv. 2022 Dec 9;8(49):eadd4187. doi: 10.1126/sciadv.add4187. Epub 2022 Dec 9. PMID:36490350[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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