Functional expression and molecular characterization of the thyrotrophin-releasing hormone receptor from the rat anterior pituitary gland

in Journal of Molecular Endocrinology
Authors:
R E Sellar
Search for other papers by R E Sellar in
Current site
Google Scholar
PubMed
Close
,
P L Taylor
Search for other papers by P L Taylor in
Current site
Google Scholar
PubMed
Close
,
R F Lamb
Search for other papers by R F Lamb in
Current site
Google Scholar
PubMed
Close
,
J Zabavnik
Search for other papers by J Zabavnik in
Current site
Google Scholar
PubMed
Close
,
L Anderson
Search for other papers by L Anderson in
Current site
Google Scholar
PubMed
Close
, and
K A Eidne
Search for other papers by K A Eidne in
Current site
Google Scholar
PubMed
Close
Restricted access
Rent on DeepDyve

Sign up for journal news

ABSTRACT

We have isolated the TRH receptor (TRH-R) from a rat anterior pituitary cDNA library, determined its sequence and examined its functional characteristics. Expression studies were carried out in Xenopus oocytes and in COS-7 cells. Microinjection of sense RNA transcripts into Xenopus oocytes showed electrophysiological responses of between 800 and 1000 nA under voltage-clamp conditions. COS-7 cells were transiently transfected with the cDNA clone under the control of a cytomegalovirus promoter and inositol phosphate (IP) measurements carried out. In TRH-R transfected cells, TRH (100 nm) produced an approximately twofold increase in total IP production. In-situ hybridization in the rat anterior pituitary revealed a heterogeneous distribution of label, a characteristic pattern of TRH-R expression. The rat 3·3 kb insert coded for a protein of 411 amino acids compared with 393 for the mouse protein. Over its length, the rat TRH-R protein showed considerable homology with that of the mouse, except for a deletion of 232 bp in the 3′-coding region. This deletion did not appear to affect the functional characteristics of the receptor, as shown by electrophysiological studies with Xenopus oocytes and by transfection of the cDNA into COS-7 cells. The sequence given for the 3′-untranslated region is 1·5 kb longer than that reported for the mouse receptor, and extends to the poly(A) tail.

 

  • Collapse
  • Expand