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.
Nagy
Stanislav
S
Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA.
Rock
Ronald S
RS
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