Journal
MOLECULAR BIOLOGY OF THE CELL
Volume 24, Issue 7, Pages 1007-1019Publisher
AMER SOC CELL BIOLOGY
DOI: 10.1091/mbc.E12-08-0568
Keywords
-
Categories
Funding
- American Heart Association Scientist Development Grant
- National Institutes of Health [R37-DK54425, R01-DK077777, P30-DK079307, R01-DK048370, R01-DK070856]
- Cellular Physiology and Kidney Imaging Cores of the Pittsburgh Center for Kidney Research [P30-DK079307]
Ask authors/readers for more resources
Multiple Rabs are associated with secretory granules/vesicles, but how these GTPases are coordinated to promote regulated exocytosis is not well understood. In bladder umbrella cells a subapical pool of discoidal/fusiform-shaped vesicles (DFVs) undergoes Rab11a-dependent regulated exocytosis in response to bladder filling. We show that Rab11a-associated vesicles are enmeshed in an apical cytokeratin meshwork and that Rab11a likely acts upstream of Rab8a to promote exocytosis. Surprisingly, expression of Rabin8, a previously described Rab11a effector and guanine nucleotide exchange factor for Rab8, stimulates stretch-induced exocytosis in a manner that is independent of its catalytic activity. Additional studies demonstrate that the unconventional motor protein myosin5B motor (Myo5B) works in association with the Rab8a-Rab11a module to promote exocytosis, possibly by ensuring transit of DFVs through a subapical, cortical actin cytoskeleton before fusion. Our results indicate that Rab11a, Rab8a, and Myo5B function as part of a network to promote stretch-induced exocytosis, and we predict that similarly organized Rab networks will be common to other regulated secretory pathways.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available