Structural highlights
Function
[MYO1C_MOUSE] Myosins are actin-based motor molecules with ATPase activity. Unconventional myosins serve in intracellular movements. Their highly divergent tails bind to membranous compartments, which then are moved relative to actin filaments. Involved in glucose transporter recycling in response to insulin by regulating movement of intracellular GLUT4-containing vesicles to the plasma membrane. Component of the hair cell's (the sensory cells of the inner ear) adaptation-motor complex. Acts as a mediator of adaptation of mechanoelectrical transduction in stereocilia of vestibular hair cells. Binds phosphoinositides and links the actin cytoskeleton to cellular membranes.[1] Isoform 3 is involved in regulation of transcription. Associated with transcriptional active ribosomal genes. Appears to cooperate with the WICH chromatin-remodeling complex to facilitate transcription. Necessary for the formation of the first phosphodiester bond during transcription initiation. [CALM_XENLA] Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases.
Publication Abstract from PubMed
Class I myosins can sense cellular mechanical forces and function as tension-sensitive anchors or transporters. How mechanical load is transduced from the membrane-binding tail to the force-generating head in myosin-1 is unknown. Here we determined the crystal structure of the entire tail of mouse myosin-1c in complex with apocalmodulin, showing that myosin-1c adopts a stable monomer conformation suited for force transduction. The lever-arm helix and the C-terminal extended PH domain of the motor are coupled by a stable post-IQ domain bound to calmodulin in a highly unusual mode. Ca(2+) binding to calmodulin induces major conformational changes in both IQ motifs and the post-IQ domain and increases flexibility of the myosin-1c tail. Our study provides a structural blueprint for the neck and tail domains of myosin-1 and expands the target binding modes of the master Ca(2+)-signal regulator calmodulin.
Structure of myosin-1c tail bound to calmodulin provides insights into calcium-mediated conformational coupling.,Lu Q, Li J, Ye F, Zhang M Nat Struct Mol Biol. 2015 Jan;22(1):81-8. doi: 10.1038/nsmb.2923. Epub 2014 Dec, 1. PMID:25437912[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hokanson DE, Laakso JM, Lin T, Sept D, Ostap EM. Myo1c binds phosphoinositides through a putative pleckstrin homology domain. Mol Biol Cell. 2006 Nov;17(11):4856-65. Epub 2006 Sep 13. PMID:16971510 doi:http://dx.doi.org/10.1091/mbc.E06-05-0449
- ↑ Lu Q, Li J, Ye F, Zhang M. Structure of myosin-1c tail bound to calmodulin provides insights into calcium-mediated conformational coupling. Nat Struct Mol Biol. 2015 Jan;22(1):81-8. doi: 10.1038/nsmb.2923. Epub 2014 Dec, 1. PMID:25437912 doi:http://dx.doi.org/10.1038/nsmb.2923
