TABLE 2.

Overview of signaling molecules involved in bitter and sweet signaling.

Signaling molecule	Bitter	Sweet
Gβ3	Rössler et al., 2000	Max et al., 2001
Gγ13	Huang et al., 1999	Max et al., 2001
PLCβ2	Rössler et al., 1998; Miyoshi et al., 2001; Yan et al., 2001; Zhang et al., 2003	Asano-Miyoshi et al., 2000; Max et al., 2001; Miyoshi et al., 2001; Zhang et al., 2003
IP3	Hwang et al., 1990; Ogura et al., 1997; Spielman, 1998; Huang et al., 1999	Bernhardt et al., 1996; Uchida and Sato, 1997; Usui-Aoki et al., 2005
IP3R	Clapp et al., 2001; Miyoshi et al., 2001	Miyoshi et al., 2001
Ca2+ release from stores	Akabas et al., 1988	Bernhardt et al., 1996; Uchida and Sato, 1997
TRPM5	Pérez et al., 2002; Zhang et al., 2003	Pérez et al., 2002; Zhang et al., 2003; Talavera et al., 2005

Involvement of the signaling molecules was demonstrated with knockout mouse models, where Ca²⁺ signals in taste bud cells, nerve responses and/or behavioral attraction were measured upon stimulation. Immunostainings were used for localization of the signaling molecules.