Overexpression of the gene for polyubiquitin in yeast confers increased secretion of a human leucocyte protease inhibitor

We have found an influence of cellular ubiquitin levels over the secretion of human leucocyte elastase inhibitor (elafin) by Saccharomyces cerevisiae. Inactivation of the UBI4 polyubiquitin gene reduced elafin secretion 3 to 4-fold. Conversely ubiquitin overexpression, by galactose induction of an integrated UBI4 gene under GAL1 promoter control, enhanced elafin secretion 7-fold compared to cells wild-type for ubiquitin genes. This influence of ubiquitin levels is exerted at a post-transcriptional step in elafin gene expression, and may represent a chaperone-like action. Ubiquitin overexpression did not affect production of alpha-factor and of certain natural yeast extracellular enzymes even though appreciable free ubiquitin became associated with the yeast periplasm.

The nucleotide sequence of a mouse renin-encoding gene, Ren-1d, and its upstream region

The renin-encoding genes have been cloned from high (Ren-1d, Ren-2d)- and low (Ren-1c)-renin-producing strains of mice (DBA/2J and C57BL/10). Each of the genes is approx. 9.6 kb in length and consists of nine exons and eight introns. The entire nucleotide sequence of the Ren-1d gene has been determined and the 5'-flanking regions of the three genes, Ren-1c, Ren-1d and Ren-2d, have been compared. The significance of several potential regulatory signals found in the DNA is discussed.

A repressor heterodimer binds to a chimeric operator

Replacement of the solvent-exposed residues of the DNA recognition helix of the 434 repressor with the corresponding residues of the P22 repressor generates a hybrid protein, 434R[alpha 3(P22R)], which binds specifically to P22 operators. We show here that a new DNA-binding specificity is generated by combining 434 and 434R[alpha 3(P22R)] repressor monomers to form a heterodimer. The heterodimer specifically recognizes a chimeric P22/434 operator that lacks two-fold rotational symmetry.

Expression of a chemically synthesized human alpha 1 interferon gene

Cells of Escherichia coli containing a chemically synthesized human alpha 1 interferon (IFN-alpha 1) gene, under control of the lac promoter, make a product with biological properties indistinguishable from those of the natural IFN-alpha 1 [antiviral activity, acid stability, species crossreactivity, inactivation by antisera directed against leukocyte or Namalwa cell interferon, and stimulation of (2'-5')oligoadenylate synthetase activity]. Similar levels of IFN synthesis were obtained when the expression unit (lac promoter plus synthetic IFN-alpha 1 gene) was transplanted into the obligate methylotroph Methylophilus methylotrophus.

Improved conversion of methanol to single-cell protein by Methylophilus methylotrophus

The glutamate dehydrogenase gene of Escherichia coli has been cloned into broad host-range plasmids and can complement glutamate synthase mutants of Methylophilus methylotrophus. Assimilation of ammonia via glutamate dehydrogenase is more energy-efficient than via glutamate synthase, thus the recombinant organism converts more growth substrate, methanol, into cellular carbon.

D-Alanine dehydrogenase. Its role in the utilisation of alanine isomers as growth substrates by Pseudomonas aeruginosa PA01

Pseudomonas aeruginosa PA01 was found to utilise both the D- and L-isomers of alpha-alanine and also beta-alanine as sole sources of carbon and energy for growth. Enzymological studies of wild-type cultures and comparison with mutants deficient in growth upon one or more isomers of alanine led to the following conclusions: (i) utilisation of D-alanine involved its direct oxidation by an inducible, membrane-bound, cytochrome-linked dehydrogenase; (ii) utilisation of L-alanine required its conversion to the directly oxidisable D-form by a soluble racemase; (iii) utilisation of beta-alanine, like L-alanine, involves both the racemase and D-alanine dehydrogenase enzymes, but in addition must involve other enzymes the identity of which is still speculative; (iv) P. aeruginosa, like Escherichia coli, appears to take up D-alanine and L-alanine by means of two specific permeases.