Dexamethasone‐dependent expression of β1–24 corticotropin stimulated adenylate cyclase during adipose conversion of 3T3‐F442A cells

FEBS Letters

Feve, Bruno¹  Pairault, Jacques¹ 

[1] U 282 de l'Institut National de la Santé et de la Recherche Médicale, Hôpital Henri Mondor, 94010 Creteil, France

关键词: Dexamethasone;    Adenylate cyclase;    ACTH receptor;    Differentiation;    (3T3 preadipocyte);    GTPγS;    guanosine 5′-(3-O-thio)triphosphate;    ACTH(1–24);    synthetic tetracosapeptide (1–24) of adrenocorticotropic hormone;    G/F(Gi;    Gs;    Go) the regulatory component of adenylate cyclase which appears to be a site of action of guanine nucleotides;    adenylate cyclase or ATP pyrophosphate ly-ase (EC 4.6.1.1);    creatine phosphokinase or ATP:creatine N-phosphotransferase (EC 2.7.3.2);    glycerophosphate dehydrogenase activity (EC 1.1.1.8);   

DOI  :  10.1016/0014-5793(87)81190-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When 3T3-F442A preadipocytes were grown in culture media supplemented with corticosteroid poor fetal calf serum and insulin they differentiated into adipocytes. Glycerophosphate dehydrogenase, a marker of terminal differentiation, developed a 600-fold increase of activity whereas the adenylate cyclase system remained unresponsive to the synthetic ACTH(1–24) analog. In contrast, 3T3-F442A adipocytes, differentiated in the presence of dexamethasone, exhibited an adenylate cyclase activity which was stimulated 4-fold by ACTH(1–24). The stimulation of the adenylate cyclase activity by GTPγS remained unchanged (about 20–25-fold) suggesting that the G regulatory coupling protein was not functionally modified by dexamethasone. Binding studies with ¹²⁵I-ACTH revealed that specific cellular binding could be evidenced in dexamethasone-treated cells while control adipocytes did not exhibit any specific binding of ¹²⁵ I-ACTH. These findings lend support to the hypothesis that the setting off of this ACTH responsiveness in 3T3-F442A cells is regulated by dexamethasone after cells are committed to adipose differentiation.

【 授权许可】

Unknown