Substrate-induced nuclear export and peripheral compartmentalization of hepatic glucokinase correlates with glycogen deposition.
Int J Exp Diabetes Res
; 2(3): 173-86, 2001.
Article
en En
| MEDLINE
| ID: mdl-12369705
ABSTRACT
Hepatic glucokinase (GK) is acutely regulated by binding to its nuclear-anchored regulatory protein (GKRP). Although GK release by GKRP is tightly coupled to the rate of glycogen synthesis, the nature of this association is obscure. To gain insight into this coupling mechanism under physiological stimulating conditions in primary rat hepatocytes, we analyzed the subcellular distribution of GK and GKRP with immunofluorescence, and glycogen deposition with glycogen cytochemical fluorescence, using confocal microscopy and quantitative image analysis. Following stimulation, a fraction of the GK signal translocated from the nucleus to the cytoplasm. The reduction in the nuclear to cytoplasmic ratio of GK, an index of nuclear export, correlated with a >50% increase in glycogen cytochemical fluorescence over a 60 min stimulation period. Furthermore, glycogen accumulation was initially deposited in a peripheral pattern in hepatocytes similar to that of GK. These data suggest that a compartmentalization exists of both active GK and the initial sites of glycogen deposition at the hepatocyte surface.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Proteínas Portadoras
/
Núcleo Celular
/
Glucoquinasa
/
Hígado
/
Glucógeno Hepático
Límite:
Animals
Idioma:
En
Revista:
Int J Exp Diabetes Res
Asunto de la revista:
ENDOCRINOLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos