Expression using fused genes providing for protein product

Abstract

Novel methods and compositions are provided for enhanced yield of heterologous proteins in fungi. The method and compositions involve employing fusion sequences involving a sequence encoding a heterologous product produced in relatively large amount as a stable polypeptide in the host fused to a second sequence in open reading frame with the prior sequence coding for a different heterologous polypeptide, where the two polypeptides are joined by a selectively cleavable linkage. In particular, a sequence coding for superoxide dismutase is joined to another polypeptide of interest at either terminus of the superoxide dismutase in a yeast expression vector under transcriptional control of an active promoter and the vector introduced into a yeast host and the host grown. High yields of the fusion product are obtained in this manner, where the fusion product can be selectively cleaved so as to produce both the superoxide dismutase and the other polypeptide in high yield. The S. cerevisiae strain 2150-2-3 (pYASI1) was deposited at the A.T.C.C. on Feb. 27, 1985 and given accession No. 20745. The S. cerevisiae strain AB110 (pYLUIGF2-14) was deposited at the A.T.C.C. on Mar. 19, 1986 and given accession No. 20796.