Expression of GABA receptor rho 1 and rho 2 subunits in the retina and brain of the rat.
We have investigated the distribution of GABA receptor rho 1 and rho 2 subunits in the rat central nervous system. Cloning of rat rho 1 and rho 2 cDNA fragments revealed similarities to the corresponding human sequences of 99% (rho 1) and 88% (rho 2) at the protein level. Whereas the human rho 2 subunit has no consensus sequence for phosphorylation by protein kinase C, the cytoplasmic loop of the rat sequence contains two such sites. Use of the polymerase chain reaction with reverse-transcribed total RNA (RT-PCR) from different brain tissues revealed that transcript for the rho 1 subunit was present in the retina only. The rho 2 mRNA was detected in all brain regions, with the highest level of expression in the retina. In situ hybridization of retinal sections revealed that rho 1 and rho 2 transcripts are present in the inner nuclear layer. RT-PCR and in situ hybridization of isolated retinal cells showed that both rho subunits are present in rod bipolar cells. Since these cells express bicuculline-insensitive GABA receptors, our results further support the idea that rho subunits are part of the GABAc receptor.
Enz
R
R
Max-Planck-Institut für Hirnforschung, Frankfurt, Germany.
Brandstätter
J H
JH
Hartveit
E
E
Wässle
H
H
Bormann
J
J
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D003001:Cloning, Molecular; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D016133:Polymerase Chain Reaction; D051381:Rats; D017208:Rats, Wistar; D018079:Receptors, GABA / Q000378:metabolism*; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D014018:Tissue Distribution
D015345:Oligonucleotide Probes; D018079:Receptors, GABA