| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on March 16, 2005
Accepted on April 27, 2005
Department of Biochemistry and Molecular Biology, University of New Hampshire, 46 College Road, Durham, NH 03824
* To whom correspondence should be addressed. E-mail: sasower{at}cisunix.unh.edu.
A full-length transcript encoding a functional type II gonadotropin-releasing hormone (GnRH) receptor was cloned from the pituitary of the sea lamprey, Petromyzon marinus. The current study is the first to identify a pituitary GnRH receptor transcript in an agnathan, which is the oldest vertebrate lineage. The cloned receptor retains the conserved structural features and amino acid motifs of other known GnRH receptors and notably includes a C-terminal intracellular tail of 
120 amino acids, the longest C-terminal tail of any vertebrate GnRH receptor identified to date. The lamprey GnRH receptor was shown to activate the inositol phosphate (IP) signaling system; stimulation with either lamprey GnRH-I or lamprey GnRH-III led to dose dependent responses in transiently transfected COS7 cells. Furthermore, analyses of serially truncated lamprey GnRH receptor mutants indicate perturbations of the C-terminal tail disrupts IP accumulation, however the tail-less lamprey GnRH receptor was not only functional, but was also capable of stimulating IP levels equal to wild-type. Expression of the receptor transcript was demonstrated in the pituitary and testes using RT-PCR, while in situ hybridization showed expression and localization of the transcript in the proximal pars distalis of the pituitary. The phylogenetic placement, structural and functional features of this GnRH receptor suggest that it is representative of an ancestral GnRH receptor. In addition to having an important role in lamprey reproductive processes, the extensive C-terminal tail of this lamprey GnRH receptor may have great significance for understanding the evolutionary change of this vital structural feature within the GnRH receptor family.
This article has been cited by other articles:
 |
|
 |
|
  S. I. Kavanaugh, M. Nozaki, and S. A. Sower Origins of Gonadotropin-Releasing Hormone (GnRH) in Vertebrates: Identification of a Novel GnRH in a Basal Vertebrate, the Sea Lamprey Endocrinology, August 1, 2008; 149(8): 3860 - 3869. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. R Sedgley, A. R Finch, C. J Caunt, and C. A McArdle Intracellular gonadotropin-releasing hormone receptors in breast cancer and gonadotrope lineage cells J. Endocrinol., December 1, 2006; 191(3): 625 - 636. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Morgan, R. Sellar, A. J. Pawson, Z.-L. Lu, and R. P. Millar Bovine and Ovine Gonadotropin-Releasing Hormone (GnRH)-II Ligand Precursors and Type II GnRH Receptor Genes Are Functionally Inactivated Endocrinology, November 1, 2006; 147(11): 5041 - 5051. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M R Silver and S A Sower Functional characterization and kinetic studies of an ancestral lamprey GnRH-III selective type II GnRH receptor from the sea lamprey, Petromyzon marinus. J. Mol. Endocrinol., June 1, 2006; 36(3): 601 - 610. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
