Distinct roles for luminal acidification in apical protein sorting and trafficking in zebrafish.

Journal Article (Journal Article)

Epithelial cell physiology critically depends on the asymmetric distribution of channels and transporters. However, the mechanisms targeting membrane proteins to the apical surface are still poorly understood. Here, we performed a visual forward genetic screen in the zebrafish intestine and identified mutants with defective apical targeting of membrane proteins. One of these mutants, affecting the vacuolar H+-ATPase gene atp6ap1b, revealed specific requirements for luminal acidification in apical, but not basolateral, membrane protein sorting and transport. Using a low temperature block assay combined with genetic and pharmacologic perturbation of luminal pH, we monitored transport of newly synthesized membrane proteins from the TGN to apical membrane in live zebrafish. We show that vacuolar H+-ATPase activity regulates sorting of O-glycosylated proteins at the TGN, as well as Rab8-dependent post-Golgi trafficking of different classes of apical membrane proteins. Thus, luminal acidification plays distinct and specific roles in apical membrane biogenesis.

Full Text

Duke Authors

Cited Authors

  • Levic, DS; Ryan, S; Marjoram, L; Honeycutt, J; Bagwell, J; Bagnat, M

Published Date

  • April 6, 2020

Published In

Volume / Issue

  • 219 / 4

PubMed ID

  • 32328632

Pubmed Central ID

  • PMC7147097

Electronic International Standard Serial Number (EISSN)

  • 1540-8140

Digital Object Identifier (DOI)

  • 10.1083/jcb.201908225


  • eng

Conference Location

  • United States