TABLE 3.
Changes in transcript levels of P. pastoris secretion- and stress-related genes due to recombinant protein secretion
| Common name | S. cerevisiae ORF designation | trp/wt ratioa | Descriptionb |
|---|---|---|---|
| BFR2 | YDR299W | 1.7 | Essential protein possibly involved in secretion; multicopy suppressor of sensitivity to brefeldin A |
| BMH2 | YDR099W | 1.6 | 14-3-3 protein isoform; binds proteins and DNA, involved in regulation of many processes, including exocytosis and vesicle transport |
| COG6 | YNL041C | 2.1 | Component of the conserved oligomeric Golgi complex (Cog1p through Cog8p), a cytosolic tethering complex that functions in protein trafficking to mediate fusion of transport vesicles to Golgi compartments |
| COY1 | YKL179C | 1.9 | Golgi membrane protein with similarity to mammalian CASP; genetic interactions with GOS1, involved in tethering of transport vesicles and in the organization of the Golgi stack |
| CUP5 | YEL027W | 4.3 | Proteolipid subunit of the V-ATPase V0 sector (subunit c; dicyclohexylcarbodiimide binding subunit); required for vacuolar acidification and important for copper and iron metal ion homeostasis |
| ERO1 | YML130C | #NV | Pdi oxidase; glycoprotein required for oxidative protein folding in the ER, protein thiol-disulfide exchange |
| HAC1 | YFL031W | #NV | bZIP transcription factor that regulates the unfolded protein response, via UPRE binding, and membrane biogenesis |
| IMH1 | YLR309C | 2.1 | Protein involved in vesicular transport; mediates transport between an endosomal compartment and the Golgi; contains a Golgi localization (GRIP) domain |
| KAR2 | YJL034W | 2.0 | Binding protein BiP, an ATPase involved in protein import into the ER, acts as a chaperone to mediate protein folding in the ER; regulates the unfolded protein response, involved in ER quality control and ER-associated degradation |
| KIN2 | YLR096W | 2.1 | Serine/threonine protein kinase involved in regulation of exocytosis; localizes to the cytoplasmic face of the plasma membrane |
| PDI1 | YCL043C | 2.9 | Protein disulfide isomerase catalyzes the formation and isomerization of disulfide bonds during the folding of secretory proteins |
| SEC31 | YDL195W | 2.4 | COPII coat of secretory pathway vesicle component (p150), involved in protein transport from endoplasmic reticulum to Golgi, structural molecule |
| SSA4 | YER103W | 3.4 | Cytoplasmic member of 70-kDa heat shock protein family, chaperone activity, involved in cotranslational targeting and translocation of nascent polypeptides into the ER |
| SSE1 | YPL106C | 2.2 | Chaperonine in the HSP110 subclass of the HSP70 family, nuclease exchange factors for HSP70 chaperones, ATPase of the Hsp90 chaperone complex; binds unfolded proteins; localized to the cytoplasm |
| SSO2 | YMR183C | 2.1 | Plasma membrane t-SNARE involved in fusion of secretory vesicles at the plasma membrane; syntaxin homolog that is functionally redundant with Sso1 |
a
Ratios of the average gene expression levels of the P. pastoris expression strain X33+pPICZαB_trypsinogen (trp) and the nonexpressing control X33 (wt) during methanol-induced recombinant protein expression in fed batch fermentations, hybridized to S. cerevisiae cDNA microarrays. #NV indicates genes that gave no signal in the microarray experiment.
b
The functions of the putative secretion helper factors are derived from the S. cerevisiae homologs of the P. pastoris genes (adapted from the Saccharomyces Genome Database [http://www.yeastgenome.org]).