Detection of sweet and umami taste in the absence of taste receptor T1r3.
The tastes of sugars (sweet) and glutamate (umami) are thought to be detected by T1r receptors expressed in taste cells. Molecular genetics and heterologous expression implicate T1r2 plus T1r3 as a sweet-responsive receptor,and T1r1 plus T1r3,as well as a truncated form of the type 4 metabotropic glutamate receptor (taste-mGluR4),as umami-responsive receptors. Here,we show that mice lacking T1r3 showed no preference for artificial sweeteners and had diminished but not abolished behavioral and nerve responses to sugars and umami compounds. These results indicate that T1r3-independent sweet- and umami-responsive receptors and/or pathways exist in taste cells.
Damak
Sami
S
Department of Biophysics and Physiology, Mount Sinai School of Medicine, Box 1677, 1425 Madison Avenue, New York, NY 10029, USA.
Rong
Minqing
M
Yasumatsu
Keiko
K
Kokrashvili
Zaza
Z
Varadarajan
Vijaya
V
Zou
Shiying
S
Jiang
Peihua
P
Ninomiya
Yuzo
Y
Margolskee
Robert F
RF
D000818:Animals; D002814:Chorda Tympani Nerve / Q000502:physiology; D005260:Female; D005930:Glossopharyngeal Nerve / Q000502:physiology; D005947:Glucose; D007291:Inosine Monophosphate / Q000494:pharmacology; D008297:Male; D008320:Maltose; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled; D012970:Sodium Glutamate; D013549:Sweetening Agents; D013649:Taste; D013650:Taste Buds / Q000502:physiology*
D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D013549:Sweetening Agents; C431926:taste receptors, type 1; D007291:Inosine Monophosphate; D008320:Maltose; D005947:Glucose; D012970:Sodium Glutamate