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.
Pharmacology, Toxicology and Pharmaceutical Science
1
5%
Biochemistry, Genetics and Molecular Biology
1
5%
Nursing and Health Professions
1
5%
Other
2
9%
Unknown
11
50%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 26 August 2018.
All research outputs
#12,374,117
of 34,457,357 outputs
Outputs from American Journal of Physiology: Cell Physiology
#1,763
of 4,841 outputs
Outputs of similar age
#37,991
of 89,074 outputs
Outputs of similar age from American Journal of Physiology: Cell Physiology
#9
of 23 outputs
Altmetric has tracked 34,457,357 research outputs across all sources so far. This one is in the 38th percentile – i.e., 38% of other outputs scored the same or lower than it.
So far Altmetric has tracked 4,841 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 5.9. This one is in the 35th percentile – i.e., 35% of its peers scored the same or lower than it.
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We're also able to compare this research output to 23 others from the same source and published within six weeks on either side of this one. This one is in the 4th percentile – i.e., 4% of its contemporaries scored the same or lower than it.
