Rab27a co-ordinates actin-dependent transport by controlling organelle-associated motors and track assembly proteins

Noura Alzahofi, Tobias Welz, Christopher L. Robinson, Emma L. Page, Deborah A. Briggs, Amy K. Stainthorp, James Reekes, David A. Elbe, Felix Straub, Wouter W. Kallemeijn, Edward W. Tate, Philip S. Goff (+8 others)
2020 Nature Communications  
Cell biologists generally consider that microtubules and actin play complementary roles in long- and short-distance transport in animal cells. On the contrary, using melanosomes of melanocytes as a model, we recently discovered that the motor protein myosin-Va works with dynamic actin tracks to drive long-range organelle dispersion in opposition to microtubules. This suggests that in animals, as in yeast and plants, myosin/actin can drive long-range transport. Here, we show that the SPIRE-type
more » ... hat the SPIRE-type actin nucleators (predominantly SPIRE1) are Rab27a effectors that co-operate with formin-1 to generate actin tracks required for myosin-Va-dependent transport in melanocytes. Thus, in addition to melanophilin/myosin-Va, Rab27a can recruit SPIREs to melanosomes, thereby integrating motor and track assembly activity at the organelle membrane. Based on this, we suggest a model in which organelles and force generators (motors and track assemblers) are linked, forming an organelle-based, cell-wide network that allows their collective activity to rapidly disperse the population of organelles long-distance throughout the cytoplasm.
doi:10.1038/s41467-020-17212-6 pmid:32661310 fatcat:3cb57bys4zec7jn6jbbazo2gwu