Inhibition of adenylyl cyclase by caveolin peptides.
Inhibition of adenylyl cyclase by caveolin peptides.
复制标题
DOI：
10.1210/endo.139.4.5957
复制
发表时间：
1998-04
期刊：
影响因子：
4.8
通讯作者：
Y. Toya;C. Schwencke;J. Couet;M. Lisanti;Y. Ishikawa
中科院分区：
文献类型：
--
作者：
Y. Toya;C. Schwencke;J. Couet;M. Lisanti;Y. Ishikawa
小凹及其主要成分小凹蛋白在 G 蛋白介导的跨膜信号传导中发挥着重要作用。我们使用源自 Caveolin-1 N 末端支架结构域的 20 聚体肽检查了 Caveolin 是否与腺苷酸环化酶（G 蛋白信号转导效应子）相互作用。当检查组织腺苷酸环化酶时，发现心脏腺苷酸环化酶比其他组织腺苷酸环化酶受到更有效的抑制。 Caveolin-1 肽抑制昆虫细胞中过度表达的 V 型和 III 型腺苷酸环化酶，而相同的肽对 II 型腺苷酸环化酶没有影响。 Caveolin-3 支架结构域肽同样抑制 V 型腺苷酸环化酶。相反，源自caveolin-2支架结构域和caveolin-1非支架结构域的肽则没有效果。动力学研究表明，caveolin-1 肽降低了 V 型的最大速率 (Vmax) 值，而不改变底物 ATP 的米氏常数 (Km) 值。对这种肽的各种截短和点突变的研究表明，至少 16 个氨基酸残基和完整的芳香族残基对于抑制作用非常重要。与基础条件相比，当腺苷酸环化酶处于刺激条件下时，抑制效力更大。因此，小窝蛋白可能是调节腺苷酸环化酶催化活性的另一种细胞成分。我们的结果还表明，小窝蛋白肽可用作腺苷酸环化酶的异构体选择性抑制剂。
Caveolae and their principal component caveolin have been implicated in playing a major role in G protein-mediated transmembrane signaling. We examined whether caveolin interacts with adenylyl cyclase, an effector of G protein signaling, using a 20-mer peptide derived from the N-terminus scaffolding domain of caveolin-1. When tissue adenylyl cyclases were examined, cardiac adenylyl cyclase was inhibited more potently than other tissue adenylyl cyclases. The caveolin-1 peptide inhibited type V, as well as type III adenylyl cyclase, overexpressed in insect cells, whereas the same peptide had no effect on type II. The caveolin-3 scaffolding domain peptide similarly inhibited type V adenylyl cyclase. In contrast, peptides derived from the caveolin-2 scaffolding domain and a caveolin-1 nonscaffolding domain had no effect. Kinetic studies showed that the caveolin-1 peptide decreased the maximal rate (Vmax) value of type V without changing the Michaelis constant (Km) value for the substrate ATP. Studies with various truncations and point mutations of this peptide revealed that a minimum of 16 amino acid residues and intact aromatic residues are important for the inhibitory effect. The potency of inhibition was greater when adenylyl cyclase was in stimulated condition vs. basal condition. Thus, caveolin may be another cellular component that regulates adenylyl cyclase catalytic activity. Our results also suggest that the caveolin peptide may be used as an isoform-selective inhibitor of adenylyl cyclase.