Interaction with the IQ3 motif of myosin-10 is required for calmodulin-like protein-dependent filopodial extension.
Calmodulin-like protein (CLP) is a specific light chain of unconventional myosin-10 (Myo10) and enhances Myo10-dependent filopodial extension. Here we show that phenylalanine-795 in the third IQ domain (IQ3) of Myo10 is critical for CLP binding. Remarkably, mutation of F795 to alanine had little effect on calmodulin binding to IQ3. Fluorescence microscopy and time-lapse video microscopy showed that HeLa cells expressing CLP and transiently transfected with GFP-Myo10-F795A exhibited significantly shorter filopodia and decreased intrafilopodial motility compared to wildtype GFP-Myo10-transfected cells. Thus, F795 represents a unique anchor for CLP and is essential for CLP-mediated Myo10 function in filopodial extension and motility.
Cell Biology and Genetics Program, Mayo Graduate School, Rochester, MN 55905, USA.
Richard D
RD
Bennett
Ariel J
AJ
Caride
Amy S
AS
Mauer
Emanuel E
EE
Strehler
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009218:Myosins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010649:Phenylalanine / Q000235:genetics; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D011554:Pseudopodia / Q000378:metabolism* / Q000648:ultrastructure
C082965:CALML3 protein, human; D002147:Calmodulin; C498718:MYO10 protein, human; D010649:Phenylalanine; D009218:Myosins