Involved in modulation of glucose-regulated gene expression. Together with MTH1, represses the hexose transporter (HXT) genes in conditions of low glucose. Stimulates the SNF1 kinase by an interaction with the catalytic domain that antagonizes autoinhibition and promotes an active conformation of the kinase. Interacts with SNF1 kinase; via catalytic domain. Interacts with the glucose sensors SNF3 and RGT2. The prion state [GAR+] is provoked by the interaction of the two proteins STD1 and PMA1. It involves a complex between a small fraction of the cellular complement of PMA1, and STD1, a much lower-abundance protein, and it is transmissible by non-Mendelian, cytoplasmic inheritance. [GAR+] makes cells resistant to the glucose-associated repression of alternative carbon sources. In contrast to other prion forms, [GAR+] cannot be cured by GdnHCl or by inactivation of the molecular chaperone HSP104. Present with 238 molecules/cell in log phase SD medium. To yeast MTH1.