Mastoparan, a peptide toxin from wasp venom, stimulates glycogenolysis mediated by an increase of the cytosolic free Ca2+ concentration but not by an increase of cAMP in rat hepatocytes

FEBS Letters

Yagami, Tatsurou¹  Matsubara, Takashi¹  Tohkin, Masahiro¹ 

[1] Shionogi Research Laboratories, Shionogi and Co. Ltd., Fukushima-ku, Osaka 553, Japan

关键词: Cyclic AMP;    Cytosolic free Ca2+;    Mastoparan;    Phospholipase C;    Phosphorylase;    (Rat hepatocyte);   

DOI  :  10.1016/0014-5793(90)80098-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A wasp venom, mastoparan, rapidly increased the cytosolic free Ca²⁺ concentration ([Ca²⁺]_i) and activated phosphorylase in rat hepatocytes in a concentration-dependent manner. Mastoparan could increase [Ca²⁺]_i even in the absence of extracellular Ca²⁺, but a larger increase was observed in the presence of extracellular Ca²⁺. Thus, mastoparan mobilized Ca²⁺ from intracellular and extracellular Ca²⁺ stores. It also activated inositol triphosphate (IP₃) accumulation, but did not stimulate cAMP production. From these results, we conclude that mastoparan activates rat hepatic glycogenolysis mediated by the accumulation of IP₃, which causes an increase of [Ca²⁺]_i but not that mediated by cAMP.

【 授权许可】

Unknown