The arabinose transporter MtLat-1 is involved in hemicellulase induction in Myceliophthora

In this study, we investigated the role of L-arabinose transporter MtLat-1 in the induction of hemicellulase genes of M. thermophila. The deletion of MtLat-1 dramatically improved protein secretion and hemicellulase activities on arabinan. Comparative transcriptomic analysis indicated MtLat-1 repressed expression of hemcellulase genes. Furthermore, based on analyses of non-transporting MtLat-1 mutant, we found MtLat-1 in M. thermophila was involved in arabinose transportation, sensing, and tdownstream signalling cascades. Additionally, we also demonstrated Mtlat-1 expression is directly regulated by transcription factor MtAra-1 and MtAra-1 is involved in L-arabinose transporter and metabolism and arabinan hydrolysis. mRNA profiles of Myceliophthora thermophila cells exposed to L-arabinose, D-xylose, D-glucose, and arabinan