GgaEX0006276 @ galGal4

Rab10 can interact with myosin Va, myosin Vb, and myosin Vc. Rab10 localized to a system of tubules and vesicles that have partially overlapping localization with Rab8a. Both Rab8a and Rab10 were mislocalized by the expression of dominant-negative myosin V tails. Interaction with Rab10 was dependent on the presence of the alternatively spliced exon D in myosin Va (HsaEX0041195) and myosin Vb (HsaEX0041208) and the homologous region in myosin Vc. Yeast two-hybrid assays and fluorescence resonance energy transfer studies confirmed that Rab10 binding to myosin V tails in vivo required the alternatively spliced exon D. In contrast to these previous work, the authors found that Rab11a can interact with both myosin Va and myosin Vb tails independent of their splice isoform.

Myosin Va is a widely expressed actin-based motor protein that binds members of the Rab GTPase family (3A, 8A, 10, 11A, 27A) and is implicated in many intracellular trafficking processes. To these knowledge, myosin Va has not been tested in a systematic screen for interactions with the entire Rab GTPase family. To that end, the authors report a yeast two-hybrid screen of all human Rabs for myosin Va-binding ability and reveal 10 novel interactions (3B, 3C, 3D, 6A, 6A_, 6B, 11B, 14, 25, 39B), which include interactions with three new Rab ++subfamilies (Rab6, Rab14, Rab39B). Different Myo5A isoforms where tested including isoform D (includes cassette exon D (HsaEX0041195)), and isoform F (includes cassette exon F (HsaEX0041194)). Of interest, myosin Va interacts with only a subset of the Rabs associated with the endocytic recycling and post-Golgi secretory systems. The authors demonstrate that myosin Va has three distinct Rab-binding domains on disparate regions of the motor (central stalk, an alternatively spliced exon, and the globular tail). Although the total pool of myosin Va is shared by several Rabs, Rab10 and Rab11 appear to be the major determinants of its recruitment to intracellular membranes. The authors also present evidence that myosin Va is necessary for maintaining a peripheral distribution of Rab11- and Rab14-positive endosomes. Note, the Myo5a isoforms show some differences in interactome.