Gurmarin sensitivity of sweet taste responses is associated with co-expression patterns of T1r2, T1r3, and gustducin.
Gurmarin (Gur) is a peptide that selectively suppresses sweet taste responses in rodents. The inhibitory effect of Gur differs among tongue regions and mouse strains. Recent studies demonstrated that co-expression levels of genes controlling sweet receptors (T1r2/T1r3 heterodimer) versus Galpha-protein, gustducin, are much lower in Gur-insensitive posterior circumvallate papillae than in Gur-sensitive anterior fungiform papillae. Here, we investigated the potential link of Gur-sensitivity with the co-expression for T1r2/T1r3 receptors and gustducin by comparing those of taste tissues of Gur-sensitive (B6, dpa congenic strains) and Gur-weakly-sensitive (BALB) strains. The results indicated that co-expression ratios among T1r2, T1r3, and gustducin in the fungiform papillae were significantly lower in Gur-weakly-sensitive BALB mice than in Gur-sensitive B6 and dpa congenic mice. This linkage between Gur-sensitivity and co-expression for T1r2/T1r3 receptors versus gustducin suggests that gustducin may be a key molecule involved in the pathway for Gur-sensitive sweet responses.
Shigemura
Noriatsu
N
Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Nakao
Kazuko
K
Yasuo
Toshiaki
T
Murata
Yoshihiro
Y
Yasumatsu
Keiko
K
Nakashima
Akihiko
A
Katsukawa
Hideo
H
Sako
Noritaka
N
Ninomiya
Yuzo
Y
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D005810:Multigene Family / Q000502:physiology; D010940:Plant Proteins / Q000008:administration & dosage*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013649:Taste / Q000187:drug effects / Q000502:physiology*; D051195:Toll-Like Receptor 2 / Q000378:metabolism*; D051196:Toll-Like Receptor 3 / Q000378:metabolism*; D014059:Tongue / Q000187:drug effects / Q000502:physiology*; D015293:Transducin / Q000378:metabolism*
D010940:Plant Proteins; C519703:TLR3 protein, mouse; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; D051196:Toll-Like Receptor 3; C075206:Gurmarin protein, Gymnema sylvestre; C075192:gustducin; D015293:Transducin