Expression of G-protein alpha subunit genes in the vestibular periphery of Rattus norvegicus and their chromosomal mapping. Acta Otolaryngol 2003 Dec;123(9):1027-34
Date
01/09/2004Pubmed ID
14710903DOI
10.1080/00016480310000773Scopus ID
2-s2.0-0346880165 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
OBJECTIVE: Heterotrimeric G-proteins play an important role in mediating signals transduced across the cell membrane by membrane-bound receptors. The precise role of G-proteins and their coupled receptors in the physiology of the vestibular neuroepithelium is not well understood. The purpose of this study was to better define the role of these proteins by examining their expression in the rat vestibular periphery and characterizing their chromosomal location.
MATERIAL AND METHODS: To characterize G-protein alpha subunit gene expression in the target tissue of interest, we performed polymerase chain reaction (PCR) using degenerate G-protein primers corresponding to conserved regions in the G-protein alpha subunit coding sequence on a normalized rat vestibular cDNA library. PCR amplicons were cloned and 50 clones were randomly selected and sequenced. Radiation hybrid (RH) mapping was used to determine the chromosomal location of G alpha(olf) and two previously identified G-protein alpha subunits--G alpha(i2) and G alpha(i2(vest))--in the rat genome.
RESULTS: The following G-protein alpha subunits were identified in the normalized cDNA library: G alpha(olf), G alpha(s), G alpha(o) and G alpha(s2). G alpha(olf) maps to chromosome 18 between markers D18Mit17b and D18Mgh2. G alpha(i2) maps to chromosome 8 between markers D8Rat65 and D8Mgh2. G alpha(i2(vest)) maps to chromosome 1 between markers D1Rat132 and D1Rat202. These chromosomal locations in the rat genome are syntenic to chromosomal regions in which the homologous G-protein alpha subunit genes have been localized in the human and mouse genomes, further validating RH mapping as an effective and accurate tool. We were unable to RH map the location of G alpha(o) due to its extensive homology with the hamster gene.
CONCLUSION: The characterization of G-protein alpha subunit gene expression in the vestibular periphery and the chromosomal localization of these genes in the rat revealed that a diverse group of these second messengers are expressed.
Author List
Cioffi JA, Erbe CB, Raphael R, Kwitek AE, Tiwari UK, Jacob HJ, Popper P, Wackym PAAuthor
Anne E. Kwitek PhD Professor in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Amino Acid SequenceAnimals
DNA, Complementary
Female
GTP-Binding Protein alpha Subunits
Gene Expression
Heterotrimeric GTP-Binding Proteins
Male
Polymerase Chain Reaction
Radiation Hybrid Mapping
Rats
Receptors, G-Protein-Coupled
Vestibule, Labyrinth