Calcium-dependent action of hypertrehalosemic hormone on activation of glycogen phosphorylase in cockroach fat body.
Calcium-dependent action of hypertrehalosemic hormone on activation of glycogen phosphorylase in cockroach fat body.
复制标题
高海藻糖激素对蟑螂脂肪体糖原磷酸化酶激活的钙依赖性作用。
DOI：
10.1016/0303-7207(95)03715-2
复制
发表时间：
1996
影响因子：
4.1
通讯作者：
Keeley,LL
中科院分区：
文献类型：
--
作者：
Park,JH;Keeley,LL
以热带蟑螂的脂肪体为材料，体外研究了盘状芽囊线虫高海藻糖化激素(BLD-HrTH)依赖的糖原磷酸化酶激活的信号机制。在无细胞外Ca~(2+)的情况下，用BLD-HrTH短暂处理脂肪体，可显着激活磷酸化酶。尽管BLD-HrTH对磷酸化酶的完全激活需要细胞外钙离子，但在无细胞外钙离子的刺激下，细胞内钙离子也参与了BLD-HrTH的信号转导。Thapsigargin和硫柳汞通过不同的机制从细胞内的钙离子储存库中动员钙离子，并且这两种化学物质都能有效地刺激磷酸化酶的活性，与最大剂量的Bld-HrTH一样有效。BLD-HrTH可能诱导细胞内钙离子释放，随后细胞外钙离子跨质膜进入。三磷酸肌醇(InsP3)水平显著升高，且呈时间和剂量依赖性，提示InsP3可能是Bld-HrTH细胞内钙离子动员的第二信使。
Signaling mechanisms for Blaberus discoidalis hypertrehalosemic hormone (Bld-HrTH)-dependent glycogen phosphorylase activation were investigated in vitro using fat body of the tropical cockroach, B. discoidalis. Brief treatment of fat bodies with Bld-HrTH in the absence of extracellular Ca2+showed a significant activation of phosphorylase. Although extracellular Ca2+was required for a full activation of phosphorylase by Bld-HrTH, stimulation in the absence of extracellular Ca2+suggested that intracellular Ca2+was also involved in Bld-HrTH signal transduction. Thapsigargin and thimerosal mobilize Ca2+from intracellular stores by different mechanisms, and both chemicals stimulated phosphorylase activities as effectively as a maximum dose of Bld-HrTH. Bld-HrTH likely induces intracellular Ca2+release followed by extracellular Ca2+entry across the plasma membrane. Inositol-1,4,5-trisphosphate (InsP3) levels were greatly increased by Bld HrTH in a time- and dose-dependent manner, suggesting that InsP3might be a Ca2+-mobilizing intracellular second messenger for Bld-HrTH.