Role of Conserved Transmembrane Domain Cysteines in Activation of Metabotropic Glutamate Receptor Subtype 6Kalyan C Tirupula1, Harpreet Kaur Dhiman1, Leelavati Murthy1,3, Alessandro Bisello2 and Judith Klein-Seetharaman1*
- *Corresponding Author:
- Judith Klein-Seetharaman
Assistant Professor, Department of Structural Biology
University of Pittsburgh School of Medicine, Room 2051
Biomedical Science Tower 3,3501 Fifth Avenue
Pittsburgh, PA 15261, USA
E-mail: [email protected]
Received date: June 28, 2012; Accepted date: September 13, 2012; Published date: September 15, 2012
Citation: Tirupula KC, Dhiman HK, Murthy L, Bisello A, Klein-Seetharaman J (2012) Role of Conserved Transmembrane Domain Cysteines in Activation of Metabotropic Glutamate Receptor Subtype 6. Med chem 2:119-125. doi:10.4172/2161-0444.1000126
Copyright: © 2012 Tirupula KC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Metabotropic glutamate receptor subtype 6 (mGluR6) is a Class C type G protein coupled receptor (GPCR) uniquely expressed on retinal bipolar cells. mGluR6 plays a key role in dim-light vision but little is known about its structure and function. Here, we characterized the role of the three transmembrane (TM) cysteines in activation through site-directed mutagenesis. Function of the receptors in cells and membranes was assayed using cAMP and G protein activation, respectively. Cysteine mutants in TM helix V displayed slightly elevated or wild-type like activity. In contrast, all mutations involving the cysteine in TM helix VI lacked agonist response. Our results suggest that TM VI plays a key role in Class C activation similar to that observed in rhodopsin-like (Class A) GPCRs.