Recombinant expression platform, constructs and methods for expression of Difficult to Express Proteins (DTE-Ps)

A versatile recombinant expression platform comprising:

• i. an array of one or more episomal or integrated yeast based expression vectors operably linked with one or more promoters selected from Gal1 promoter, ADH2 promoter or Gal10 promoter;
• wherein the promoters can be used singly or in combination;
• the said vector comprising an auxotrophic selection marker selected from Ura3 or Leu2;
• a terminator CYCT1;
• an Ampicillin resistance marker;
• an origin of replication site pUC ori;
• a 2 micron origin;
• one or more specific upstream regulatory sequences and a sequence region comprising of multiple cloning sites;
• wherein said vector directs insertion of full length or truncated polynucleotide sequence for desired target proteins;
• into the host cell;
• ii. engineered protease deficient yeast host cell with disrupted endogenous genes encoding protease PRB1, protease PEP4 and auxotrophic markers uracil, lysine, adenine and leucine;
• and
• wherein said platform allows for enhanced expression of difficult to express proteins of diverse origin and families.