γ13与味觉传导素在味觉受体细胞中共定位，并介导对苦味剂苯甲地那铵的肌醇三磷酸反应。

Ggamma13 colocalizes with gustducin in taste receptor cells and mediates IP3 responses to bitter denatonium.

作者信息

Huang L, Shanker Y G, Dubauskaite J, Zheng J Z, Yan W, Rosenzweig S, Spielman A I, Max M, Margolskee R F

机构信息

Howard Hughes Medical Institute, Mount Sinai School of Medicine of New York University, Box 1677, One Gustave L. Levy Place, New York, New York 10029, USA.

出版信息

Nat Neurosci. 1999 Dec;2(12):1055-62. doi: 10.1038/15981.

DOI:10.1038/15981

PMID:10570481

Abstract

Gustducin is a transducin-like G protein selectively expressed in taste receptor cells. The alpha subunit of gustducin (alpha-gustducin) is critical for transduction of responses to bitter or sweet compounds. We identified a G-protein gamma subunit (Ggamma13) that colocalized with alpha-gustducin in taste receptor cells. Of 19 alpha-gustducin/Ggamma13-positive taste receptor cells profiled, all expressed the G protein beta3 subunit (Gbeta3); approximately 80% also expressed Gbeta1. Gustducin heterotrimers (alpha-gustducin/Gbeta1/Ggamma13) were activated by taste cell membranes plus bitter denatonium. Antibodies against Ggamma13 blocked the denatonium-induced increase of inositol trisphosphate (IP3) in taste tissue. We conclude that gustducin heterotrimers transduce responses to bitter and sweet compounds via alpha-gustducin's regulation of phosphodiesterase (PDE) and Gbetagamma's activation of phospholipase C (PLC).

摘要

味觉传导素是一种在味觉受体细胞中选择性表达的类似转导素的G蛋白。味觉传导素的α亚基（α-味觉传导素）对于苦味或甜味化合物反应的转导至关重要。我们鉴定出一种G蛋白γ亚基（Gγ13），它与α-味觉传导素在味觉受体细胞中共定位。在分析的19个α-味觉传导素/Gγ13阳性味觉受体细胞中，所有细胞均表达G蛋白β3亚基（Gβ3）；约80%的细胞还表达Gβ1。味觉细胞膜加上苦味剂苯甲地那铵可激活味觉传导素异源三聚体（α-味觉传导素/Gβ1/Gγ13）。抗Gγ13抗体可阻断苯甲地那铵诱导的味觉组织中肌醇三磷酸（IP3）的增加。我们得出结论，味觉传导素异源三聚体通过α-味觉传导素对磷酸二酯酶（PDE）的调节以及Gβγ对磷脂酶C（PLC）的激活来转导对苦味和甜味化合物的反应。