Methylotrophic yeast Pichia pastoris is an object of modern biotechnology. Decisive understanding of gene regulation mechanisms is essential for successful protein production. In this study, we investigated the effect of deletions in P. pastoris genes encoding proteins, homologous to S. serevisiae Rtg1p, Rtg 2p, Msn2p and Msn4p. It was shown, that deletion in PpRTG1 gene results in inability of P. pastoris to grow on medium with methanol as a carbon source and ammonium sulfate as a source of nitrogen. We also demonstrate that deletions in PpRTG1 and PpRTG2 decrease activity of AOX1 promoter.