Genetic evidence that cholera toxin substrates are regulatory components of adenylate cyclase.
Genetic evidence that cholera toxin substrates are regulatory components of adenylate cyclase.
复制标题
遗传证据表明霍乱毒素底物是腺苷酸环化酶的调节成分。
DOI：
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发表时间：
1978
影响因子：
4.8
通讯作者：
H. Bourne
中科院分区：
文献类型：
--
作者：
G. Johnson;H. Kaslow;H. Bourne
Cholera toxin, using [32P]NAD+ as substrate, specifically radiolabels at least two proteins in plasma membranes of wild type S49 mouse lymphoma cells. The toxin-specific substrates are detectable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as bands corresponding to molecular weights of 45,000 and a doublet of 52,000 to 53,000. Membranes of two other cell types exhibit similar patterns of radiolabeled bands specifically produced by incubation with cholera toxin: the "uncoupled" variant S49 cell, which possesses adenylate cyclase activity unresponsive to hormones, and the HTC4 rat hepatoma cell, which lacks detectable catalytic adenylate cyclase activity but contains components of the cyclase system necessary for regulation by guanyl nucleotides and NaF. Little or no toxin-specific radiolabeling is observed in membranes of a fourth cell type, the adenylate cyclase activity-deficient S49 variant, which functionally lacks components of the cyclase system involved in cholera toxin action and regulation by guanyl nucleotides and NaF. The toxin-specific labeling pattern is not observed in membranes prepared from wild type S49 cells previously treated with cholera toxin in culture. One or both of the toxin substrates thus appears to be involved in regulation of adenylate cyclase by guanyl nucleotides and fluoride ion.
