REPETITIVE SEGMENTAL STRUCTURE OF THE TRANSDUCIN BETA-SUBUNIT - HOMOLOGY WITH THE CDC4 GENE AND IDENTIFICATION OF RELATED MESSENGER-RNAS
REPETITIVE SEGMENTAL STRUCTURE OF THE TRANSDUCIN BETA-SUBUNIT - HOMOLOGY WITH THE CDC4 GENE AND IDENTIFICATION OF RELATED MESSENGER-RNAS
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DOI：
10.1073/pnas.83.7.2162
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发表时间：
1986-04-01
影响因子：
11.1
通讯作者：
SIMON, MI
中科院分区：
文献类型：
--
作者：
FONG, HKW;HURLEY, JB;SIMON, MI
视网膜转导蛋白是一种鸟嘌呤核苷酸调节蛋白（称为G蛋白），可激活感光细胞中的cGMP磷酸二酯酶，由三个亚基组成。我们已经鉴定并分析了牛转导蛋白.beta的cDNA克隆。可能与其他 G 蛋白中的亚基高度保守或相同。从整个编码区的cDNA核苷酸序列，推导出340个氨基酸的蛋白质的一级结构。编码的 .beta。亚基的Mr为37,375，由串联排列的重复同源片段组成。此外，β-亚基和酵母CDC4基因产物之间存在一级结构和片段序列的显着同源性。先生 37,375 .beta。亚基多肽由 2.9 千碱基 (kb) mRNA 编码。然而，在视网膜中存在基于寡核苷酸和引物延伸探针杂交的与2.9-kb mRNA不同的其他β相关mRNA。已检查的所有哺乳动物组织和克隆细胞系均含有至少两个β相关mRNA，长度通常为1.8和2.9kb。这些结果表明mRNA是少数密切相关的基因或单个高度复杂的β的加工产物。基因。
Retinal transducin, a guanine nucleotide regulatory protein (referred to as a G protein) that activates a cGMP phosphodiesterase in photoreceptor cells, is comprised of three subunits. We have identified and analyzed cDNA clones of the bovine transducin .beta. subunit that may be highly conserved or identical to that in other G proteins. From the cDNA nucleotide sequence of the entire coding region, the primary structure of a 340-amino acid protein was deduced. The encoded .beta. subunit has a Mr of 37,375 and is comprised of repetitive homologous segments arranged in tandem. Furthermore, significant homology in primary structure and segmental sequence exists between the .beta.-subunit and the yeast CDC4 gene product. The Mr 37,375 .beta. subunit polypeptide is encoded by a 2.9-kilobase (kb) mRNA. However, there exists in retina other .beta.-related mRNAs that are divergent from the 2.9-kb mRNA on the basis of oligonucleotide and primer-extended probe hybridizations. All mammalian tissues and clonal cell lines that have been examined contain at least two .beta.-related mRNAs, usually 1.8 and 2.9 kb in length. These results suggest that the mRNAs are the processed products of a small number of closely related genes or of a single highly complex .beta. gene.