Li T S, Volpp K, Applebury M L
Department of Ophthalmology and Visual Sciences, University of Chicago, IL 60637.
Proc Natl Acad Sci U S A. 1990 Jan;87(1):293-7. doi: 10.1073/pnas.87.1.293.
A full-length cDNA clone encoding the alpha' subunit of cGMP phosphodiesterase (PDE) from bovine cone photoreceptors was selected by probing a retinal library with a DNA fragment encoding the catalytic core of the rod cGMP PDE alpha subunit. Identity of the clone was confirmed by comparing its deduced sequence with cone PDE peptide sequences determined by Charbonneau et al. [Charbonneau, H., Prusti, R. K., LeTrong, H., Sonnenburg, W. K., Mullaney, P. J., Walsh, K. A. & Beavo, J. A. (1990) Proc. Natl. Acad. Sci. USA, pp. 288-292]. The cone PDE alpha' and the rod PDE alpha and beta subunits are encoded by distinct genes. cGMP PDE subunits share a common ancestry with cAMP PDEs and cyclic nucleotide-binding proteins. Sequence comparisons predict the presence of a catalytic core and possible secondary sites for noncatalytic cGMP binding. The presence of a C-terminal CAAX (Cys-aliphatic-aliphatic-Xaa) motif suggests the cone enzyme may be posttranslationally modified by proteolysis, methylation, and isoprenylation.
通过用编码视杆细胞环磷酸鸟苷磷酸二酯酶（PDE）α亚基催化核心的DNA片段探测视网膜文库，筛选出了一个编码牛视锥光感受器环磷酸鸟苷磷酸二酯酶（PDE）α'亚基的全长cDNA克隆。通过将其推导序列与Charbonneau等人[Charbonneau, H., Prusti, R. K., LeTrong, H., Sonnenburg, W. K., Mullaney, P. J., Walsh, K. A. & Beavo, J. A. (1990) Proc. Natl. Acad. Sci. USA, pp. 288 - 292]确定的视锥PDE肽序列进行比较，证实了该克隆的身份。视锥PDEα'亚基以及视杆PDEα和β亚基由不同的基因编码。环磷酸鸟苷磷酸二酯酶亚基与环磷酸腺苷磷酸二酯酶和环核苷酸结合蛋白有着共同的祖先。序列比较预测存在一个催化核心以及非催化性环磷酸鸟苷结合的可能二级位点。C末端CAAX（半胱氨酸-脂肪族-脂肪族-Xaa）基序的存在表明视锥酶可能通过蛋白水解、甲基化和异戊二烯化进行翻译后修饰。
