Myosin-X, a novel myosin with pleckstrin homology domains, associates with regions of dynamic actin.
Myosin-X is the founding member of a novel class of unconventional myosins characterized by a tail domain containing multiple pleckstrin homology domains. We report here the full-length cDNA sequences of human and bovine myosin-X as well as the first characterization of this protein's distribution and biochemical properties. The 235 kDa myosin-X contains a head domain with <45% protein sequence identity to other myosins, three IQ motifs, and a predicted stalk of coiled coil. Like several other unconventional myosins and a plant kinesin, myosin-X contains both a myosin tail homology 4 (MyTH4) domain and a FERM (band 4.1/ezrin/radixin/moesin) domain. The unique tail domain also includes three pleckstrin homology domains, which have been implicated in phosphatidylinositol phospholipid signaling, and three PEST sites, which may allow cleavage of the myosin tail. Most intriguingly, myosin-X in cultured cells is present at the edges of lamellipodia, membrane ruffles, and the tips of filopodial actin bundles. The tail domain structure, biochemical features, and localization of myosin-X suggest that this novel unconventional myosin plays a role in regions of dynamic actin.
Berg
J S
JS
Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Derfler
B H
BH
Pennisi
C M
CM
Corey
D P
DP
Cheney
R E
RE
D000199:Actins / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D015152:Blotting, Northern; D002154:Calpain / Q000378:metabolism; D002417:Cattle; D002458:Cell Fractionation; D002460:Cell Line; D021961:Cell Membrane Structures / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D017124:Conserved Sequence; D015638:Cytochalasin D / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D007668:Kidney; D008954:Models, Biological; D008969:Molecular Sequence Data; D009218:Myosins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D000199:Actins; D001798:Blood Proteins; D018076:DNA, Complementary; C498718:MYO10 protein, human; D010750:Phosphoproteins; D012333:RNA, Messenger; C039077:platelet protein P47; D015638:Cytochalasin D; D002154:Calpain; D009218:Myosins