AJP - Regu Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol (May 25, 2006). doi:10.1152/ajpregu.00078.2006
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
291/4/R1157    most recent
00078.2006v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bewley, M. S
Right arrow Articles by Forrest, Jr., J. N
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bewley, M. S
Right arrow Articles by Forrest, Jr., J. N
Submitted on January 29, 2006
Accepted on May 8, 2006

Shark Rectal Gland Vasoactive Intestinal Peptide Receptor: Cloning, Functional Expression, and Regulation of CFTR Chloride Channels

Marie S Bewley1, John T G Pena1, Florian N. Plesch1, Sarah E Decker1, Gerhard J Weber1, and John N Forrest, Jr.1*

1 Internal Medicine Department, Yale University School of Medicine, New Haven, Connecticut, United States; Mount Desert Island Biological Laboratory, Salisbury Cove, Maine, United States

* To whom correspondence should be addressed. E-mail: john.forrest{at}yale.edu.

Vasoactive intestinal peptide (VIP) is a secretagogue that mediates chloride secretion in intestinal epithelia. We determined the relative potency of VIP and related peptides in the rectal gland of the elasmobranch dogfish shark, and cloned and expressed the VIP receptor from this species. In the perfused rectal gland, VIP (5 nM) stimulated chloride secretion from 250 ± 66 to 2469 ± 186 µEq/h/g; the relative potency of peptide agonists was VIP > PHI = GHRH > PACAP > secretin. The cloned VIP receptor from shark rectal gland is only 61% identical to the human VIP-R1 receptor. It maintains a long extracellular N-terminus with 7 cysteine residues, and has 3 N-glycosylation sites and 8 other residues implicated in VIP binding. Two amino acids considered important for peptide binding in mammals are not present in the shark orthologue. When shark VIP-R and the CFTR chloride channel were coexpressed in Xenopus oocytes, VIP increased chloride conductance from 11.3 ± 2 to 127 ± 34 µS. The agonist affinity for activating chloride conductance by the cloned receptor was VIP > GHRH = PHI > PACAP > secretin, a profile mirroring that in the perfused gland. The receptor differs from previously cloned VIP receptors in having a low affinity for PACAP. Expression of both VIP-R and CFTR mRNA was detected by quantitative PCR in shark rectal gland, intestine, and brain. These studies characterize a unique G protein coupled receptor from the shark rectal gland that is the oldest cloned VIP receptor.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 2006 by the American Physiological Society.