Abstract: Methods are provided for producing protein products in host cells and for selecting transformed cells comprising the step of transforming the host cell with a DNA molecule comprising a gene which complements a deficiency in the host cell. The host cell is s strain having a deficiency in a function necessary for normal cell growth. The gene in the DNA molecule, such as a plasmid, which complements the deficiency serves as a selection marker whereby the growth conditions for selection may comprise a conventional complex medium.

Abstract: Methods are provided for producing protein products in host cells and for selecting transformed cells comprising the step of transforming the host cell with a DNA molecule comprising a gene which complements a deficiency in the host cell. The host cell is s strain having a deficiency in a function necessary for normal cell growth. The gene in the DNA molecule, such as a plasmid, which complements the deficiency serves as a selection marker whereby the growth conditions for selection may comprise a conventional complex medium.

Abstract: A method for the cell-free synthesis and isolation of novel genes and polypeptides is provided. Within one embodiment, an expression unit is constructed onto which semi-random nucleotide sequences are attached. The semi-random nucleotide sequences are first transcribed to produce RNA, and then translated under conditions such that polysomes are produced. Polysomes which bind to a substance of interest are then isolated and disrupted; and the released mRNA is recovered. The mRNA is used to construct cDNA which is expressed to produce novel polypeptides.

Abstract: A method for the cell-free synthesis and isolation of novel genes and polypeptides is provided. Within one embodiment, an expression unit is constructed onto which semi-random nucleotide sequences are attached. The semi-random nucleotide sequences are first transcribed to produce RNA, and then translated under conditions such that polysomes are produced. Polysomes which bind to a substance of interest are then isolated and disrupted; and the released mRNA is recovered. The mRNA is used to construct cDNA which is expressed to produce novel polypeptides.

Abstract: Promoters associated with expression of specific enzymes in the glycolytic pathway are used for expression of alien DNA, particularly yeast promoters known to provide high enzyme levels of enzymes in the glycolytic pathway are employed for expressing a mammalian protein, such as .alpha..sub.1 -antitrypsin. The promoters include promoters involved in expression of pyruvate kinase, triose phosphate isomerase, phosphoglucose isomerase, phosphoglycerate mutase, hexokinase 1, hexokinase 2, glucokinase, phosphofructokinase, and aldolase, as well as the glycolytic regulation gene. Particularly, the glycolytic regulation gene can be used in conjunction with promoters in the glycolytic pathway for regulated production of desired proteins.

Abstract: A method is provided for expressing human alpha-1-antitrypsin in yeast utilizing a wild-type strain and a hyperproduction mutant, GK100.

Abstract: Promoters associated with expression of specific enzymes in the glycolytic pathway are used for expression of alien DNA, particularly yeast promoters known to provide high enzyme levels of enzymes in the glycolytic pathway are employed for expressing a mammalian protein, such as .alpha..sub.1 -antitrypsin. The promoters include promoters involved in expression of pyruvate kinase, triose phosphate isomerase, phosphoglucose isomerase, phosphoglycerate mutase, hexokinase 1, hexokinase 2, glucokinase, phosphofructokinase, and aldolase, as well as the glycolytic regulation gene. Particularly, the glycolytic regulation gene can be used in conjuction with promoters in the glycolytic pathway for regulated production of desired proteins.