A V0-ATPase-dependent apical trafficking pathway maintains the polarity of the intestinal absorptive membrane

Abstract

Intestine function relies on the strong polarity of intestinal epithelial cells and the array of microvilli forming a brush border at their luminal pole. Combining genetic RNAi screen and in vivo super-resolution imaging in the C. elegans intestine, we uncovered that the V0 sector of the V-ATPase (V0-ATPase) controls a late apical trafficking step, involving RAB-11 endosomes and the SNARE SNAP-29, necessary to maintain the polarized localization of both apical polarity modules and brush border proteins. We show that the V0-ATPase pathway also genetically interacts with glycosphingolipids in enterocyte polarity maintenance. Finally, we demonstrate that depletion of the V0-ATPase fully recapitulates the severe structural, polarity and trafficking defects observed in enterocytes from patients with Microvillus inclusion disease (MVID) and used this new in vivo MVID model to follow the dynamics of microvillus inclusions. Hence, we describe a new function for the V0-ATPase in apical trafficking and epithelial polarity maintenance and the promising use of C. elegans intestine as an in vivo model to better understand the molecular mechanisms of rare genetic enteropathies.\n\nSummary statementV0-ATPase controls a late apical trafficking step involved in the maintenance of the apical absorptive intestinal membrane and its depletion phenocopies the trafficking and structural defects of MVID in C. elegans.