An oligopeptide transporter gene family in Phanerochaete chrysosporium

Oligopeptide transporters are believed to translocate their substrates across the membrane from the extracellular environment into cell. In the present study, sixteen oligopeptide transporter (OPT) orthologs (PcOPT1 to PcOPT16) were identified in Phanerochaete chrysosporium strain BKMF1767. They were predicted to encode integral membrane proteins with 13 to 16 transmembrane domains. The cDNA and genomic sequences of these genes were confirmed by clone sequencing and Transcriptome Sequencing. Based on sequence similarities, the PcOPT genes can be grouped into three different subfamilies. Comprehensive analysis revealed correlations between gene groupings and gene structures. The PcOPT genes showed differential expression patterns at different metabolic stages or in various stress conditions, suggesting that they may play different functional roles. PcOPT14 was able to mediate the uptake of tetrapeptide KLGL when heterologously expressed in Saccharomyces cerevisiae. This study provides some basic genomic information for OPT genes in P. chrysosporium and will be useful for elucidating their roles in growth, stress response and survival of this organism. Moreover, the results can help us to better understand the complexity of metabolism of P. chrysosporium.