The protein phosphatase-1 targeting subunit TIMAP regulates LAMR1 phosphorylation.
Biochem Biophys Res Commun
; 338(3): 1327-34, 2005 Dec 23.
Article
en En
| MEDLINE
| ID: mdl-16263087
TIMAP is a prenylated endothelial cell protein with a domain structure that predicts it to be a protein phosphatase-1 (PP-1) regulatory subunit. We found that TIMAP interacts with the 37/67 kDa laminin receptor (LAMR1) in yeast two-hybrid assays. In endothelial cells, endogenous TIMAP and LAMR1 co-immunoprecipitated and co-localized at the plasma membrane. TIMAP amino acids 261-290, representing the fourth ankyrin repeat of TIMAP, are necessary and sufficient for the interaction. In MDCK cells, lacking endogenous TIMAP, overexpression of full-length TIMAP, but not TIMAP deleted in the fourth ankyrin domain, allowed co-immunoprecipitation with LAMR1. PP-1 co-precipitated with overexpressed and endogenous TIMAP in MDCK and endothelial cells, respectively. In MDCK cells, PP-1 associated with LAMR1 in the presence, but not in the absence, of TIMAP. LAMR1 was a substrate for PP-1 in vitro, and in MDCK cells its phosphorylation was abrogated by expression of full-length TIMAP but not by TIMAP deficient in the fourth ankyrin domain. Hence, TIMAP targets PP-1 to LAMR1, and LAMR1 is a TIMAP-dependent PP-1 substrate.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Receptores de Laminina
/
Fosfoproteínas Fosfatasas
/
Subunidades de Proteína
Límite:
Animals
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2005
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos