Occludin protects secretory cells from ER stress by facilitating SNARE-dependent apical protein exocytosis.

ABSTRACT: Tight junctions (TJs) are fundamental features of both epithelium and endothelium and are indispensable for vertebrate organ formation and homeostasis. However, mice lacking Occludin (Ocln) develop relatively normally to term. Here we show that Ocln is essential for mammary gland physiology, as mutant mice fail to produce milk. Surprisingly, Ocln null mammary glands showed intact TJ function and normal epithelial morphogenesis, cell differentiation, and tissue polarity, suggesting that Ocln is not required for these processes. Using single-cell transcriptomics, we identified milk-producing cells (MPCs) and found they were progressively more prone to endoplasmic reticulum (ER) stress as protein production increased exponentially during late pregnancy and l

SUBMITTER: Zhou T 

PROVIDER: S-EPMC7060669 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature