Adenylyl cyclase expression and modulation of cAMP in rat taste cells
- PMID: 12606315
- DOI: 10.1152/ajpcell.00556.2002
Adenylyl cyclase expression and modulation of cAMP in rat taste cells
Abstract
cAMP is a second messenger implicated in sensory transduction for taste. The identity of adenylyl cyclase (AC) in taste cells has not been explored. We have employed RT-PCR to identify the AC isoforms present in taste cells and found that AC 4, 6, and 8 are expressed as mRNAs in taste tissue. These proteins are also expressed in a subset of taste cells as revealed by immunohistochemistry. Alterations of cAMP concentrations are associated with transduction of taste stimuli of several classes. The involvement of particular ACs in this modulation has not been investigated. We demonstrate that glutamate, which is a potent stimulus eliciting a taste quality termed umami, causes a decrease in cAMP in forskolin-treated taste cells. The potentiation of this response by inosine monophosphate, the lack of response to d-glutamate, and the lack of response to umami stimuli in nonsensory lingual epithelium all suggest that the cAMP modulation represents umami taste transduction. Because cAMP downregulation via ACs can be mediated through Galpha(i) proteins, we examined the colocalization of the detected ACs with Galpha(i) proteins and found that 66% of AC8 immunopositive taste cells are also positive for gustducin, a taste-specific Galpha(i) protein. Whether AC8 is directly involved in signal transduction of umami taste remains to be established.
Similar articles
-
Interaction between the second messengers cAMP and Ca2+ in mouse presynaptic taste cells.J Physiol. 2009 Apr 15;587(Pt 8):1657-68. doi: 10.1113/jphysiol.2009.170555. Epub 2009 Feb 16. J Physiol. 2009. PMID: 19221121 Free PMC article.
-
Tastants evoke cAMP signal in taste buds that is independent of calcium signaling.Am J Physiol Cell Physiol. 2006 Aug;291(2):C237-44. doi: 10.1152/ajpcell.00303.2005. Epub 2006 Mar 1. Am J Physiol Cell Physiol. 2006. PMID: 16510847
-
Receptors for bitter, sweet and umami taste couple to inhibitory G protein signaling pathways.Eur J Pharmacol. 2004 Apr 12;489(3):139-49. doi: 10.1016/j.ejphar.2004.03.004. Eur J Pharmacol. 2004. PMID: 15087236
-
Umami taste transduction mechanisms.Am J Clin Nutr. 2009 Sep;90(3):753S-755S. doi: 10.3945/ajcn.2009.27462K. Epub 2009 Jul 1. Am J Clin Nutr. 2009. PMID: 19571214 Free PMC article. Review.
-
Taste receptor signalling - from tongues to lungs.Acta Physiol (Oxf). 2012 Feb;204(2):158-68. doi: 10.1111/j.1748-1716.2011.02308.x. Epub 2011 May 7. Acta Physiol (Oxf). 2012. PMID: 21481196 Free PMC article. Review.
Cited by
-
Adrenomedullin Enhances Mouse Gustatory Nerve Responses to Sugars via T1R-Independent Sweet Taste Pathway.Nutrients. 2023 Jun 28;15(13):2941. doi: 10.3390/nu15132941. Nutrients. 2023. PMID: 37447268 Free PMC article.
-
G Protein-Coupled Receptors in Taste Physiology and Pharmacology.Front Pharmacol. 2020 Nov 30;11:587664. doi: 10.3389/fphar.2020.587664. eCollection 2020. Front Pharmacol. 2020. PMID: 33390961 Free PMC article. Review.
-
Interaction between the second messengers cAMP and Ca2+ in mouse presynaptic taste cells.J Physiol. 2009 Apr 15;587(Pt 8):1657-68. doi: 10.1113/jphysiol.2009.170555. Epub 2009 Feb 16. J Physiol. 2009. PMID: 19221121 Free PMC article.
-
Tonic activity of Galpha-gustducin regulates taste cell responsivity.FEBS Lett. 2008 Nov 12;582(27):3783-7. doi: 10.1016/j.febslet.2008.10.007. Epub 2008 Oct 16. FEBS Lett. 2008. PMID: 18930056 Free PMC article.
-
Mammalian Taste Cells Express Functional Olfactory Receptors.Chem Senses. 2019 May 29;44(5):289-301. doi: 10.1093/chemse/bjz019. Chem Senses. 2019. PMID: 31140574 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources