Koller K J, de Sauvage F J, Lowe D G, Goeddel D V
Department of Molecular Biology, Genentech, Inc., South San Francisco, California 94080.
Mol Cell Biol. 1992 Jun;12(6):2581-90. doi: 10.1128/mcb.12.6.2581-2590.1992.
The natriuretic peptide receptors, NPR-A and NPR-B, are two members of the newly described class of receptor guanylyl cyclases. The kinaselike domain of these proteins is an important regulator of the guanylyl cyclase activity. To begin to understand the molecular nature of this type of regulation, we made complete and partial deletions of the kinase domain in NPR-A and NPR-B. We also made chimeric proteins in which the kinase domains of NPR-A and NPR-B were exchanged or replaced with kinase domains from structurally similar proteins. Complete deletion of the kinase homology domain in NPR-A and NPR-B resulted in constitutive activation of the guanylyl cyclase. Various partial deletions of this region produced proteins that had no ability to activate the enzyme with or without hormone stimulation. The kinase homology domain can be exchanged between the two subtypes with no effect on regulation. However, structurally similar kinaselike domains, such as from the epidermal growth factor receptor or from the heat-stable enterotoxin receptor, another member of the receptor guanylyl cyclase family, were not able to regulate the guanylyl cyclase activity correctly. These findings suggest that the kinaselike domain of NPR-A and NPR-B requires strict sequence conservation to maintain proper regulation of their guanylyl cyclase activity.
利钠肽受体NPR - A和NPR - B是新描述的受体鸟苷酸环化酶类别的两个成员。这些蛋白质的激酶样结构域是鸟苷酸环化酶活性的重要调节因子。为了开始了解这种调节类型的分子本质，我们对NPR - A和NPR - B中的激酶结构域进行了完全和部分缺失。我们还构建了嵌合蛋白，其中NPR - A和NPR - B的激酶结构域被交换或被结构相似蛋白质的激酶结构域所取代。NPR - A和NPR - B中激酶同源结构域的完全缺失导致鸟苷酸环化酶的组成型激活。该区域的各种部分缺失产生的蛋白质无论有无激素刺激都没有激活该酶的能力。激酶同源结构域可以在两种亚型之间交换而不影响调节。然而，结构相似的激酶样结构域，如来自表皮生长因子受体或来自热稳定肠毒素受体（受体鸟苷酸环化酶家族的另一个成员）的结构域，不能正确调节鸟苷酸环化酶活性。这些发现表明，NPR - A和NPR - B的激酶样结构域需要严格的序列保守性来维持其鸟苷酸环化酶活性的适当调节。
