Structured post-IQ domain governs selectivity of myosin X for fascin-actin bundles.
Without guidance cues, cytoskeletal motors would traffic components to the wrong destination with disastrous consequences for the cell. Recently, we identified a motor protein, myosin X, that identifies bundled actin filaments for transport. These bundles direct myosin X to a unique destination, the tips of cellular filopodia. Because the structural and kinetic features that drive bundle selection are unknown, we employed a domain-swapping approach with the nonselective myosin V to identify the selectivity module of myosin X. We found a surprising role of the myosin X tail region (post-IQ) in supporting long runs on bundles. Moreover, the myosin X head is adapted for initiating processive runs on bundles. We found that the tail is structured and biases the orientation of the two myosin X heads because a targeted insertion that introduces flexibility in the tail abolishes selectivity. Together, these results suggest how myosin motors may manage to read cellular addresses.
Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA.
Stanislav
S
Nagy
Ronald S
RS
Rock
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle; D002645:Chickens; D008840:Microfilament Proteins / Q000378:metabolism*; D009068:Movement; D024701:Myosin Type V; D009218:Myosins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity
D000199:Actins; D002352:Carrier Proteins; D008840:Microfilament Proteins; C409064:Myo10 protein, mouse; C020324:fascin; D024701:Myosin Type V; D009218:Myosins