RRC ID 64287
Author Izumi Y, Furuse K, Furuse M.
Title The novel membrane protein Hoka regulates septate junction organization and stem cell homeostasis in the Drosophila gut.
Journal J Cell Sci
Abstract Smooth septate junctions (sSJs) regulate the paracellular transport in the intestinal tract in arthropods. In Drosophila, the organization and physiological function of sSJs are regulated by at least three sSJ-specific membrane proteins: Ssk, Mesh and Tsp2A. Here, we report a novel sSJ membrane protein, Hoka, which has a single membrane-spanning segment with a short extracellular region, and a cytoplasmic region with Tyr-Thr-Pro-Ala motifs. The larval midgut in hoka mutants shows a defect in sSJ structure. Hoka forms a complex with Ssk, Mesh and Tsp2A, and is required for the correct localization of these proteins to sSJs. Knockdown of hoka in the adult midgut leads to intestinal barrier dysfunction and stem cell overproliferation. In hoka-knockdown midguts, aPKC is upregulated in the cytoplasm and the apical membrane of epithelial cells. The depletion of aPKC and yki in hoka-knockdown midguts results in reduced stem cell overproliferation. These findings indicate that Hoka cooperates with the sSJ proteins Ssk, Mesh and Tsp2A to organize sSJs, and is required for maintaining intestinal stem cell homeostasis through the regulation of aPKC and Yki activities in the Drosophila midgut.
Volume 134(6)
Published 2021-3-26
DOI 10.1242/jcs.257022
PII jcs.257022
PMID 33589496
IF 4.573
Resource
Drosophila 13704R-1 TBX-0002 TBX-0004 TBX-0007 CAS-0002 TBX-0010 DGRC#112001 DGRC#108851