Koesling D, Schultz G, Böhme E
Institut für Pharmakologie, Freie Universität Berlin, Germany.
FEBS Lett. 1991 Mar 25;280(2):301-6. doi: 10.1016/0014-5793(91)80317-v.
The cyclic GMP-forming enzyme guanylyl cyclase exists in cytosolic and in membrane-bound forms differing in structure and regulations. Determination of the primary structures of the guanylyl cyclases revealed that the cytosolic enzyme form consists of two similar subunits and that membrane-bound guanylyl cyclases represent enzyme forms in which the catalytic part is located in an intracellular, C-terminal domain and is regulated by an extracellular, N-terminal receptor domain. A domain of 250 amino acids conserved in all guanylyl cyclases appears to be required for the formation of cyclic nucleotide, as this homologous domain is also found in the cytosolic regions of the adenylyl cyclase. The general structures of guanylyl cyclases shows similarities with other signal transducing enzymes such as protein-tyrosine phosphatases and protein-tyrosine kinases, which also exist in cytosolic and receptor-linked forms.
生成环鸟苷酸的鸟苷酸环化酶以胞质形式和膜结合形式存在，二者在结构和调节方面有所不同。对鸟苷酸环化酶一级结构的测定表明，胞质酶形式由两个相似的亚基组成，而膜结合型鸟苷酸环化酶的酶形式中，催化部分位于细胞内的C末端结构域，并受细胞外的N末端受体结构域调节。所有鸟苷酸环化酶中保守的一个250个氨基酸的结构域似乎是形成环核苷酸所必需的，因为在腺苷酸环化酶的胞质区域也发现了这个同源结构域。鸟苷酸环化酶的总体结构与其他信号转导酶如蛋白酪氨酸磷酸酶和蛋白酪氨酸激酶相似，它们也以胞质形式和受体连接形式存在。
