HIP1 and HIP1r stabilize receptor tyrosine kinases and bind 3-phosphoinositides via epsin N-terminal homology domains.
J Biol Chem
; 279(14): 14294-306, 2004 Apr 02.
Article
em En
| MEDLINE
| ID: mdl-14732715
ABSTRACT
Huntingtin-interacting protein 1-related (HIP1r) is the only known mammalian relative of huntingtin-interacting protein 1 (HIP1), a protein that transforms fibroblasts via undefined mechanisms. Here we demonstrate that both HIP1r and HIP1 bind inositol lipids via their epsin N-terminal homology (ENTH) domains. In contrast to other ENTH domain-containing proteins, lipid binding is preferential to the 3-phosphate-containing inositol lipids, phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,5-bisphosphate. Furthermore, the HIP1r ENTH domain, like that of HIP1, is necessary for lipid binding, and expression of an ENTH domain-deletion mutant, HIP1r/deltaE, induces apoptosis. Consistent with the ability of HIP1r and HIP1 to affect cell survival, full-length HIP1 and HIP1r stabilize pools of growth factor receptors by prolonging their half-life following ligand-induced endocytosis. Although HIP1r and HIP1 display only a partially overlapping pattern of protein interactions, these data suggest that both proteins share a functional homology by binding 3-phosphorylated inositol lipids and stabilizing receptor tyrosine kinases in a fashion that may contribute to their ability to alter cell growth and survival.
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Base de dados:
MEDLINE
Assunto principal:
Fosfatidilinositóis
/
Neuropeptídeos
/
Proteínas de Transporte
/
Receptores Proteína Tirosina Quinases
/
Proteínas de Transporte Vesicular
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Proteínas de Ligação a DNA
/
Endocitose
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article