Cytoplasmic extension peptide of Pichia pastoris glucose sensor Gss1 is not compulsory for glucose signalling

Abstract

In the methylotrophic yeast, Pichia pastoris, Gss1 protein is a glucose sensor involved in pexophagy, glucose utilization and glucose catabolite repression. This study identifies that deletion of 150 residues of Gss1 affects slightly glucose catabolite repression and pexophagy, while maintaining signalling function of Gss1. Substitution of one conserved amino acid R180K of Gss1 protein has no visible phenotype, in contrast to corresponding changes in glucose sensors from other yeast species. We suggest that C-terminal cytoplasmic extension of PpGss1plays different role to that of its homologs in Saccharomyces cerevisiae and Hansenula polymorpha.