Identification of EPI64, a TBC/rabGAP domain-containing microvillar protein that binds to the first PDZ domain of EBP50 and E3KARP.

ABSTRACT: The cortical scaffolding proteins EBP50 (ERM-binding phosphoprotein-50) and E3KARP (NHE3 kinase A regulatory protein) contain two PDZ (PSD-95/DlgA/ZO-1-like) domains followed by a COOH-terminal sequence that binds to active ERM family members. Using affinity chromatography, we identified polypeptides from placental microvilli that bind the PDZ domains of EBP50. Among these are 64- and/or 65-kD differentially phosphorylated polypeptides that bind preferentially to the first PDZ domain of EBP50, as well as to E3KARP, and that we call EPI64 (EBP50-PDZ interactor of 64 kD). The gene for human EPI64 lies on chromosome 22 where nine exons specify a protein of 508 residues that contains a Tre/Bub2/Cdc16 (TBC)/rab GTPase-activating protein (GAP) domain. EPI64 terminates in DTYL, which is necessary

SUBMITTER: Reczek D 

PROVIDER: S-EPMC2185518 | biostudies-literature | 2001 Apr

REPOSITORIES: biostudies-literature