Calcium influx promotes PLEKHG4B localization to cell-cell junctions and regulates the integrity of junctional actin filaments.

ABSTRACT: PLEKHG4B is a Cdc42-targeting guanine-nucleotide exchange factor implicated in forming epithelial cell-cell junctions. Here we explored the mechanism regulating PLEKHG4B localization. PLEKHG4B localized to the basal membrane in normal Ca²⁺ medium but accumulated at cell-cell junctions upon ionomycin treatment. Ionomycin-induced junctional localization of PLEKHG4B was suppressed upon disrupting its annexin-A2 (ANXA2)-binding ability. Thus, Ca²⁺ influx and ANXA2 binding are crucial for PLEKHG4B localization to cell-cell junctions. Treatments with low Ca²⁺ or BAPTA-AM (an intracellular Ca²⁺ chelator) suppressed PLEKHG4B localization to the basal membrane. Mutations of the phosphoinositide-binding motif in the pleckstrin homology (PH) domain of PLEKH

SUBMITTER: Ninomiya K 

PROVIDER: S-EPMC10881155 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature