A novel role for vitamin K1 in a tyrosine phosphorylation cascade during chick embryogenesis.
J Clin Invest
; 99(4): 602-7, 1997 Feb 15.
Article
en En
| MEDLINE
| ID: mdl-9045861
ABSTRACT
The development of the embryo is dependent upon a highly coordinated repertoire of cell division, differentiation, and migration. Protein-tyrosine phosphorylation plays a pivotal role in the regulation of these processes. Vitamin K-dependent gamma-carboxylated proteins have been identified as ligands for a unique family (Tyro 3 and 7) of receptor tyrosine kinases (RTKs) with transforming ability. The involvement of vitamin K metabolism and function in two well characterized birth defects, warfarin embryopathy and vitamin K epoxide reductase deficiency, suggests that developmental signals from K-dependent pathways may be required for normal embryogenesis. Using a chick embryogenesis model, we now demonstrate the existence of a vitamin K1-dependent protein-tyrosine phosphorylation cascade involving c-Eyk, a member of the Tyro 12 family, and key intracellular proteins, including focal adhesion kinase (pp125FAK), paxillin, and pp60src. This cascade is sensitive to alteration in levels or metabolism of vitamin K1. These findings provide a major clue as to why, in the mammalian (and human) fetus, the K-dependent proteins are maintained in an undercarboxylated state, even to the point of placing the newborn at hemorrhagic risk. The precise regulation of vitamin K1-dependent regulatory pathways would appear to be critical for orderly embryogenesis.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Vitamina K 1
/
Proteínas Tirosina Quinasas
/
Embrión de Pollo
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Clin Invest
Año:
1997
Tipo del documento:
Article
País de afiliación:
Canadá