Linked Life Data

10764554

Source:http://linkedlifedata.com/resource/pubmed/id/10764554

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-5-11
pubmed:abstractText
Gonadotropin-releasing hormone receptors (GnRH-Rs) expressed in the pituitary of eutherian species of mammal are unique in lacking the cytoplasmic C-terminal tail characteristic of GnRH-Rs of nonmammalian vertebrates and other G protein-coupled receptors. To further investigate evolutionary relationships among vertebrate GnRH-Rs, a full-coding region cDNA of the pituitary GnRH-R was cloned from a metatherian marsupial mammal, the Australian brushtail possum (Trichosurus vulpecula). We have determined the pharmacological characteristics and internalization kinetics of this GnRH-R from an early evolved, metatherian species of mammal and compared it with the corresponding receptors in eutherian species of mammal and nonmammalian vertebrates. The predicted GnRH-R protein from the possum pituitary has high homology with the other mammalian GnRH-Rs (80% identity) and, in common with other mammals, lacks an intracellular C-terminal tail. The ligand selectivity of the possum GnRH-R transfected into COS-1 cells, assessed using inositol phosphate assays and radioreceptor binding assays, was similar to that of the other mammalian GnRH-Rs, and distinct from those of the nonmammalian GnRH-Rs. The pharmacological characteristics of the possum GnRH-R were similar to those of other mammalian GnRH-Rs, for a selection of agonists (including naturally occurring GnRH ligands and superagonists) and antagonists. Receptor-mediated internalization of GnRH agonist by the possum GnRH-R was slightly more rapid than that of the human GnRH-R, while the internalization kinetics of the chicken GnRH-R, in which a cytoplasmic C-terminal tail is present, was considerably more rapid. In terms of the evolution of the GnRH-R in vertebrates, the possum (a metatherian mammal) GnRH-R has a striking resemblance, in both structure and pharmacological characteristics, to GnRH-Rs in eutherian mammals, which are quite distinct from the nonmammalian vertebrate GnRH-Rs, and are unique among G protein-coupled receptors in lacking an intracellular C-terminal tail. The distinct structure of the pituitary GnRH-R in mammalian vertebrates is likely to have important functional consequences in the reproductive physiology of mammals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0016-6480
pubmed:author
pubmed:issnType
Print
pubmed:volume
117
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
439-48
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Cloning and expression, pharmacological characterization, and internalization kinetics of the pituitary GnRH receptor in a metatherian species of mammal.
pubmed:affiliation
Department of Chemical Pathology, University of Cape Town Medical School and Groote Schuur Hospital, South Africa. JAKING@chempath.uct.ac.za
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't