Alternative Splicing in Class V Myosins Determines Association with Rab10

Joseph T Roland,Lynne A Lapierre,James R Goldenring

doi:10.1074/jbc.m805957200

Joseph T Roland, Lynne A Lapierre + Show 1 more

Open Access

https://doi.org/10.1074/jbc.m805957200

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Abstract

Rab proteins influence vesicle trafficking pathways through the assembly of regulatory protein complexes. Previous investigations have documented that Rab11a and Rab8a can interact with the tail region of myosin Vb and regulate distinct trafficking pathways. We have now determined that a related Rab protein, 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 and myosin Vb 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 our previous work, we found that Rab11a can interact with both myosin Va and myosin Vb tails independent of their splice isoform. These results indicate that Rab GTPases regulate diverse endocytic trafficking pathways through recruitment of multiple myosin V isoforms.

Highlights

Eukaryotic cells are comprised of networks of highly organized membranous structures that require the efficient and timely movement of diverse intracellular proteins for proper function
Exon B in myosin Vb does not resemble the dynein light chain 2 (DLC2) binding region in myosin Va [27, 28], and it likely does not interact with DLC2
Previous studies have revealed that Rab27a, along with its adaptor proteins melanophilin/Slac2-a and Slac2-c/MyRIP, link myosin Va to distinct cargo membranes

Summary

Introduction

Eukaryotic cells are comprised of networks of highly organized membranous structures that require the efficient and timely movement of diverse intracellular proteins for proper function. Rab8a interacted with a construct expressing only the amino-terminal 180 amino acids of human myosin Vb tail lacking exon D (MVb-ABCE) but not a matching construct that included exon D (MVb-ABCDE).

Results

Conclusion