期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1992
卷号：89
期号：23
页码：11151-11155
DOI：10.1073/pnas.89.23.11151
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The PCR and conventional library screening were used to clone the brain-specific somatostatin receptor rSSTR-4 from a rat genomic library. The deduced amino acid sequence encodes a protein of 384 amino acids and displays structural and sequence homologies with members of the G protein-receptor superfamily. The amino acid sequence of rSSTR-4 is 60% and 48% identical to that of somatostatin receptors SSTR-1 and SSTR-2, respectively, two recently cloned subtypes. Competition curve analysis of the binding properties of the receptor transiently expressed in COS-1 cells revealed a higher apparent affinity for somatostatin 14 than for somatostatin 28. In contrast, the somatostatin analogs SMS 201-995, IM 4-28, and MK-678 failed to displace specific binding in transfected cells. These characteristics resemble the pharmacological binding properties of the previously described brain-specific somatostatin-receptor subtype. Examination of the tissue distribution of mRNA for rSSTR-4 revealed expression limited to various brain regions with highest levels in the cortex and hippocampus. Thus, based on the pharmacology and tissue localization of this receptor, we conclude that rSSTR-4 represents a brain-specific somatostatin receptor.
