Abstract: [Object] An object of the present invention is to provide a sweet taste receptor-expressing construct which can functionally stably express both of a sweet taste receptor (T1R2+T1R3) and a G protein ? subunit at a high expression efficacy, and a stable expression cell body expressing the construct. [Solution] The sweet taste receptor-expressing construct of the present invention is such that respective genes encoding sweet taste receptor subunits T1R2 and T1R3, and a G protein ? subunit are inserted into the same plasmid. The cell body of the present invention is such that the sweet taste receptor-expressing construct of the present invention is gene-introduced into a 293 cell in which an FRT (Flippase Recognition Target) sequence is incorporated into one place in a genome, to express sweet taste receptor subunits T1R2 and T1R3, and a G protein ? subunit simultaneously.

Abstract: Provided are: an NAS variant characterized by having sweetness independent of pH in the case of combination with a polypeptide NBS variant by causing substitution mutation or deletion mutation in one or several amino acids out of the amino acid residues constituting a polypeptide NAS; an NBS variant characterized by having sweetness independent of pH in the case of combination with a polypeptide NAS variant by causing substitution mutation or deletion mutation in one or several amino acids out of the amino acid residues constituting a polypeptide NBS; a dimer comprising a combination of the NAS variant and the NBS variant; a recombinant vector containing a gene encoding the NAS variant and a gene encoding the NBS variant; and a transformant containing the vector.

Abstract: [Object] An object of the present invention is to provide a human sweet taste receptor-acting sweet taste regulating substance to a sweet taste substance by which the advantageous effects such as improvement in a taste, saving of a sweetener, reduction in calorie, low caries etc. can be obtained by applying to various foods and beverages. [Solution] The sweet taste receptor-acting sweet taste regulating substance of the present invention is identified by measurement of a physiological response by a sweet taste substance, using a cultured cell strain which is allowed to express hT1R2 and hT1R3, and a G protein ? subunit, by transferring an expression construct obtained by inserting respective cDNAs encoding the hT1R2 and the hT1R3, and the G protein ? subunit into the same plasmid, into a 293 cell in which an FRT (Flippase Recognition Target) site has been incorporated into one place in a genome DNA.

Abstract: [Object] An object of the present invention is to provide a sweet taste receptor-expressing construct which can functionally stably express both of a sweet taste receptor (T1R2+T1R3) and a G protein ? subunit at a high expression efficacy, and a stable expression cell body expressing the construct. [Solution] The sweet taste receptor-expressing construct of the present invention is such that respective genes encoding sweet taste receptor subunits T1R2 and T1R3, and a G protein ? subunit are inserted into the same plasmid. The cell body of the present invention is such that the sweet taste receptor-expressing construct of the present invention is gene-introduced into a 293 cell in which an FRT (Flippase Recognition Target) sequence is incorporated into one place in a genome, to express sweet taste receptor subunits T1R2 and T1R3, and a G protein ? subunit simultaneously.

Abstract: An object of the present invention is to discover a substance with sweetness independent of pH and to provide a novel composition with sweetness characterized by containing the substance. Provided are: an NAS variant characterized by having sweetness independent of pH in the case of combination with a polypeptide NBS variant by causing substitution mutation or deletion mutation in one or several amino acids out of the amino acid residues constituting a polypeptide NAS; an NBS variant characterized by having sweetness independent of pH in the case of combination with a polypeptide NAS variant by causing substitution mutation or deletion mutation in one or several amino acids out of the amino acid residues constituting a polypeptide NBS; a diner comprising a combination of the NAS variant and the NBS variant; a recombinant vector containing a gene encoding the NAS variant and a gene encoding the NBS variant; and a transformant containing the vector.