The taste molecular biology has suggested that, among the five basic taste, sweet, bitter, and umami tastes are received by G protein-coupled receptors on taste bud cells. Recent studies on the molecular entity of the receptors have disclosed the presence of T 1 R and T 2 R. Our group has investigated the intracellular signalingmechanism following the taste reception has elucidated the involvement of the phosphoinositol turnover passway with phospholipase Cβ2 playing a central role.