Production of insulin-like growth factor-1 in methylotrophic yeast cells

A DNA fragment comprising one or more copies of an expression cassette that includes, in the direction of transcription, the following sequences of nucleotides:

• (i) a promoter region of a methanol responsive gene of a methylotrophic yeast;
• (ii) a sequence of nucleotides encoding a polypeptide consisting essentially of:
• (a) the S. cerevisiae alpha mating factor (AMF) pre-pro sequence, including the processing site:
• lys-arg, and
• (b) an insulin-like growth factor-1 (IGF-1) peptide;
• and
• (iii) a transcription terminator functional in Pichia pastoris,
• wherein:
• the sequences of nucleotides encoding the AMF sequence and the IGF-1 peptide are operationally associated, such that upon transcription and translation of the transcript, biologically active IGF-1 peptide is secreted;
• the promoter and terminator are operationally associated with the sequence of nucleotides encoding the polypeptide for transcription of the sequence of nucleotides;
• the promoter region directs methanol-induced transcription in Pichia pastoris of the sequence of nucleotides encoding the polypeptide;
• and
• the methylotrophic yeast is a species that is a member of a genus selected from the group consisting of Candida, Hansenula, Pichia, and Torulopsis that uses methanol as a sole carbon source.