PT  - JOURNAL ARTICLE
AU  - Noura Alzahofi
AU  - Christopher L. Robinson
AU  - Tobias Welz
AU  - Emma L. Page
AU  - Deborah A. Briggs
AU  - Amy K. Stainthorp
AU  - James Reekes
AU  - David A. Elbe
AU  - Felix Straub
AU  - Edward W. Tate
AU  - Philip S. Goff
AU  - Elena V. Sviderskaya
AU  - Marta Cantero
AU  - Lluis Montoliu
AU  - Maryse Bailly
AU  - Eugen Kerkhoff
AU  - Alistair N. Hume
TI  - Rab27a co-ordinates actin-dependent transport by controlling organelle-associated motors and track assembly proteins
AID  - 10.1101/314153
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 314153
4099  - http://biorxiv.org/content/early/2018/05/03/314153.short
4100  - http://biorxiv.org/content/early/2018/05/03/314153.full
AB  - 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 motor myosin-Va, works with dynamic actin tracks, to drive long-range organelle dispersion in microtubule depleted cells. This suggests that in animals, as in yeast and plants, myosin/actin can drive long-range transport. Here we show that SPIRE1/2 and formin-1 (FMN1) proteins generate actin tracks required for myosin-Va-dependent transport in melanocytes. Moreover we show that, in addition to melanophilin/myosin-Va, Rab27a can recruit SPIRE1/2 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 a cell-wide network that allows their collective activity to rapidly disperse the population of organelles long-distance throughout the cytoplasm.