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Regulation of inducible bradykinin B1 receptor gene expression through absence of internalization and resensitization
Author(s) -
Zhou Xiaofeng,
Prado Gregory N.,
Taylor Linda,
Yang Xionghu,
Polgar Peter
Publication year - 2000
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/1097-4644(20000901)78:3<351::aid-jcb1>3.0.co;2-u
Subject(s) - internalization , receptor , transfection , microbiology and biotechnology , biology , bradykinin , kallidin , 5 ht5a receptor , gene expression , bradykinin receptor , gene , kinin , biochemistry
Rapid induction and down‐regulation of bradykinin B1 receptor (BKB1R) gene expression is tightly regulated at the transcriptional and mRNA levels (Zhou et al. [1998] Biochem. J. 330:361–366; Zhou et al. [1999] Mol. Cell Biol. Res. Commun. 1:29–35). Here we explore regulation of BKB1R expression at the protein level. To make this inducible gene express constitutively, we utilized a bicistronic mammalian expression vector (pCMin) for stable transfection of the BKB1R gene into human lung fibroblasts, IMR90SV40. The BKB1R displayed a high affinity and specificity (K d = 0.5 nM) for desArg 10 ‐kallidin. The receptor mediated such signaling events as arachidonic acid (ARA) release, phosphoinositide (PI) turnover and Ca 2+ ‐flux. The receptor function proved differentially desensitized. For example, after initial exposure to desArg 10 ‐kallidin, a second stimulation with desArg 10 ‐kallidin did not induce further Ca 2+ ‐flux or ARA‐release while PI‐turnover continued unabated. Unlike most of the G‐protein coupled receptors, the BKB1R did not internalize within 60 min of exposure to 10 nM desArg 10 ‐kallidin. It also did not resensitize. Thus, the duration and signal capacity of the BKB1R at the protein level is regulated through lack of internalization, an absence of resensitization and a lack of desensitization for certain events such as PI turnover. In fact, the absence of BKB1R resensitization is likely a very important contributor to the rapid disappearance of this inducible receptor. J. Cell. Biochem. 78:351–362, 2000. © 2000 Wiley‐Liss, Inc.