Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Salmonella dublin plasmid gene vsdC is essential for virulence. We have constructed a vsdC-lacZ translational fusion to demonstrate that vsdC is selectively expressed during the stationary phase of bacterial cell growth. This pattern of expression has been confirmed by mRNA hybridization studies. Carbon starvation is able to induce vsdC expression by limiting bacterial growth. The expression of vsdC is dependent upon an upstream gene, vsdA, whose gene product possesses significant amino-terminus homology with the LysR family of transcriptional activator proteins. We have further demonstrated that vsdC expression is not dependent upon the known Salmonella chromosomal virulence regulatory loci ompR, phoP, and cya-crp and that vsdC can be expressed in a range of nontyphoidal Salmonella serovars, including some serovars in which introduction of the virulence plasmid does not confer mouse virulence. The vsd system provides a model for the study of transcriptional activation, a basis for the development of new expression vectors, and a novel mechanism of virulence gene regulation. Bacterial growth limitation within the phagosomes of host phagocytic cells may be the environmental signal inducing plasmid-mediated virulence gene expression in salmonellae.
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PMID:Growth regulation of a Salmonella plasmid gene essential for virulence. 193 84

The yeast Kluyveromyces lactis is can utilise a wide range of non-fermentable carbon compounds as sole sources of carbon and energy, and differs from Saccharomyces cerevisiae in being able to carry out oxidative and fermentative metabolism simultaneously. In S. cerevisiae, growth on all non-fermentable carbon sources requires Cat8p, a transcriptional activator that controls the expression of gluconeogenic and glyoxylate cycle genes via CSREs (Carbon Source Responsive Elements). The down-regulation of Cat8p by fermentable carbon sources is the primary factor responsible for the tight repression of gluconeogenesis by glucose in S. cerevisiae. To analyse the regulation of gluconeogenesis in K. lactis, we have cloned and characterised the K. lactis homologue of CAT8 (KlCAT8). The gene was isolated by multicopy suppression of a fog2/klsnf1 mutation, indicating a similar epistatic relationship between KlSNF1 and KlCAT8 as in the case of the S. cerevisiae homologues. KlCAT8 encodes a protein of 1445 amino acids that is 40% identical to ScCat8p. The most highly conserved block is the putative Zn(II)2Cys6 DNA-binding domain, but additional conserved regions shared with members of the zinc-cluster family from Aspergillus define a subfamily of Cat8p-related proteins. KlCAT8 complements the growth defect of a Sccat8 mutant on non-fermentable carbon sources. In K. lactis, deletion of KlCAT8 severely impairs growth on ethanol, acetate and lactate, but not on glycerol. Derepression of enzymes of the glyoxylate cycle--malate synthase and particularly isocitrate lyase--was impaired in a Klcat8 mutant, whereas Northern analysis revealed that derepression of KlFBP1 and KlPCK1 does not require KlCat8p. Taken together, our results indicate that in K. lactis gluconeogenesis is not co-regulated with the glyoxylate cycle, and only the latter is controlled by KlCat8p.
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PMID:Differences in regulation of yeast gluconeogenesis revealed by Cat8p-independent activation of PCK1 and FBP1 genes in Kluyveromyces lactis. 1101 49