GRK3
Beta-adrenergic receptor kinase 2 (EC 2.7.11.15) (Beta-ARK-2) (G-protein-coupled receptor kinase 3) [ADRBK2] [BARK2]
Publications[править]
The effects of glucagon and epinephrine on gluconeogenesis in young (4 month) and old (24 month) Fisher 344 rat hepatocytes were compared. In contrast to glucagon, which had a similar effect on gluconeogenesis in both young and old cells, epinephrine caused a smaller increase in gluconeogenesis in old rat hepatocytes than in young hepatocytes. beta2 adrenergic receptor (beta2-AR) expression slightly decreased in aged rat liver, and there were differences between young and old hepatocytes in their patterns of G protein coupled receptor kinases, which are involved in the activation of beta2-AR receptor signal desensitization. The major isoform of the kinase changed from GRK2 to GRK3 and the expression of beta-arrestin, which is recruited by the phosphorylated beta2-AR for internalization and degradation, increased in aged rat liver. GRK3 overexpression also decreased the glucose output from young rat hepatocytes. We conclude that an age-associated reduction in epinephrine-induced gluconeogenesis occurs through the epinephrine receptor desensitizing system.
MeSH Terms
- Adrenergic beta-2 Receptor Agonists
- Adrenergic beta-Agonists
- Aging
- Animals
- Epinephrine
- G-Protein-Coupled Receptor Kinase 2
- G-Protein-Coupled Receptor Kinase 3
- Glucagon
- Gluconeogenesis
- Male
- Models, Biological
- Phosphorylation
- Rats
- Rats, Inbred F344
- Receptors, Adrenergic, beta-2