The expression of cellulase CMC3 under control the alcohol oxidase 1 (AOX1) and methanol oxidase (MOX) promoters in the yeast Pichia pastoris

Small and powerful promoters play a key role in recombinant protein expression in different hosts including Pichia pastoris. In the present study, expression of cellulase beta endoglucanase CMC3 gene was studied under the control of the alcohol oxidase 1 (AOX1) and methanol oxidase (MOX) promoters, with the methanol feeding, in the yeast Pichia pastoris. To avoid the gene dosage effect, colonies harbored single copy of target constructs were screened by Real-Time PCR method. The results of enzymatic assay, zymogaphy and SDS-PAGE for the culture of single copy harboring transformants showed powerful, comparable expression of CMC3 under the control of both MOX and AOX1 promoters. High-level expression of recombinant CMC3 under control of the MOX promoter indicated that this small, new powerful promoter could be considered as a promising tool for recombinant protein production in the yeast Pichia pastoris.