Comparing cytosolic expression to peroxisomal targeting of the chimeric L1/L2 (Chi Delta H-L2) gene from human papillomavirus type 16 in the methylotrophic yeasts Pichia pastoris and Hansenula polymorpha

摘要

The chimeric ChiH-L2 gene from human papillomavirus type 16, consisting of structural proteins L1 and L2, was successfully expressed in the cytosol of both Pichia pastoris and Hansenula polymorpha during methanol induction. In addition, a novel approach was employed whereby ChiH-L2 was targeted to the peroxisome using peroxisomal targeting sequence 1 (PTS1) to compare ChiH-L2 yields in the peroxisome vs the cytosol. The ChiH-L2 gene was yeast-optimized and cloned into plasmids aimed at genomic integration. Levels of intracellular ChiH-L2 accumulation in the cytosol were highest in P. pastoris KM71 strain KMChiH-L2 (1.43mg/l), compared to the maximum production level of 0.72mg/l obtained with H. polymorpha. ChiH-L2 targeting to the peroxisome was successful; however, it appeared to negatively affect ChiH-L2 production in both P. pastoris and H. polymorpha