Identification and characterization of calcium and manganese transporting ATPase (PMR1) gene of Pichia pastoris.

A gene homologous to Saccharomyces cerevisiae PMR1 has been cloned in the methylotrophic yeast Pichia pastoris. The entire P. pastoris PMR1 gene (PpPMR1) codes a protein of 924 amino acids. Sequence analysis of the PpPMR1 cDNA and the genomic DNA revealed that there is no intron in the coding region. The putative gene product contains all of the conserved regions observed in P-type ATPases and exhibits 66.2%, 60.3% and 50.6% identity to Pichia angusta (Hansenula polymorpha), Saccharomyces cerevisiae PMR1 and human ATP2C1 gene products, respectively. A pmr1 null mutant strain of P. pastoris exhibited growth defects in media with the addition of EGTA, but with supplementation of Ca2+ to a calcium-deficient media reversed the growth defects of the mutant strain. Manganese reversed the growth defects of the mutant strain; however, the cell growth was not as profound as the Ca2+ -supplemented media. The results demonstrated that the P. pastoris gene encodes the functional homologue of the S. cerevisiae PMR1 gene product, a P-type Ca2+/Mn2+ -ATPase. The DNA sequence of the P. pastoris PMR1 gene has been submitted to GenBank under Accession No. DQ239958.