Gustducin, a Got Subunit expressed in taste cells, is known as a key molecule for sweet, Umami and bitter taste signal transduction. However, previous studies demonstrated that the contribution of gustducin to the sweet/umami responses in the posterior region of the tongue is less than that ill the anterior region, implying the existence of another G alpha subunit mediating sweet/umami taste signal transductional. Here, we Propose G alpha 14, a member of G alpha q family, as the candidate mediator. G alpha 14 was found in our Subtracted full-length cDNA library derived from mouse circumvallate papillae (CV) and expressed in a subset of taste cells in CV and foliate papillae, but not in fungiform papillae and soft palate. G alpha 14 was co-expressed with T1r3, a sweet/umami taste receptor, but not with gustducin in CV. These results suggest the important roles of G alpha 14 in sweet/umami taste signal transduction in the posterior region of the tongue. (c) 2008 Elsevier Inc. All rights reserved.