Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:5.4.2.8 (phosphomannomutase)
 238 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pseudomonas aeruginosa M60, a mucoid strain, was grown in continuous culture (D 0.05 h-1) under ammonia limitation with glucose as the carbon source. Steady-state alginate production occurred for only 1-2 d under these conditions [qalginate 0.097 g alginate h-1 (g dry wt cells)-1], after which time the percentage of mucoid cells and the alginate concentration in the culture decreased in parallel and approached zero after approximately 10 d. These changes were accompanied by similar decreases in the activities of the alginate biosynthetic enzymes (represented by phosphomannomutase and GDP-mannose dehydrogenase) and by a large increase in the activity of the first enzyme of the 'external' non-phosphorylative pathway of glucose metabolism, glucose dehydrogenase. In contrast, the activities of other enzymes associated with this pathway (gluconate dehydrogenase, 2-ketogluconate kinase plus 2-ketogluconate-6-phosphate reductase) or with the 'internal' phosphorylative pathway of glucose metabolism (glucokinase and glucose-6-phosphate dehydrogenase) remained essentially unchanged. The loss of mucoidy and alginate production was accompanied by the appearance of low concentrations of intracellular polyhydroxyalkanoate (PHA) and of extracellular gluconate and 2-ketogluconate (partly at the expense of alginate production and partly as a result of increased glucose consumption). It is suggested that ammonia-limited, glucose-excess cultures of P. aeruginosa growing at low dilution rate are unable fully to regulate the rate at which glucose and/or its 'external' pathway metabolites are taken up by the cell, and therefore form copious amounts of alginate in order both to overcome the potentially deleterious osmotic effects of accumulating surplus intracellular metabolites and to consume the surplus ATP generated by the further oxidation of these metabolites. The loss of mucoidy invokes the use of an alternative, but analogous, strategy via which non-mucoid cells produce an osmotically inactive intracellular product (PHA) plus increased amounts of the extracellular metabolites gluconate and 2-ketogluconate via the low-energy-yielding and, under these conditions, largely dead-end 'external' metabolic pathway.
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PMID:Physiological and biochemical changes accompanying the loss of mucoidy by Pseudomonas aeruginosa. 893 14

Vibrio vulnificus is thought to employ a quorum-sensing system to control the expression of a global gene. In this study, proteomes and transcriptomes of a lacZ null mutant, VvSR Delta Z, and a luxS-smcR double mutant, VvSR Delta ZSR, were compared with the parent strain, VvAR, by means of two-dimensional gel electrophoresis (2D-PAGE) and differentially displayed reverse transcriptase PCR (DDRT-PCR). 2D-PAGE analysis showed that 36 protein spots were differentially expressed, 14 of which have been identified by peptide-mass fingerprinting. The expression of eight cellular proteins was repressed by luxS and smcR mutation: Zn-dependent protease, 6-phosophofructokinase, periplasmic ABC-type Fe3(+) transport system, deoxyribose-phosphate aldolase, phosphomannomutase, orotidine-5'-phosphate decarboxylase, uridylate kinase, and an unidentified protein. These proteins are involved in virulence, adaptation to environmental stress, biosynthesis of LPS, and cell multiplication. Phage shock protein A, a chemotaxis signal transduction protein, and an uncharacterized low-complexity protein were activated in the cellular components of the luxS-smcR mutant. However, only three proteins, of unknown function, were identified in the extracellular components of the mutants. Analysis of transcriptomes with DDRT-PCR showed that two genes, phosphoribosylformylglycinamidine synthase and ATP-dependent protease HslVU protease were regulated at the transcriptional level by luxS and smcR gene mutation. The results from this study show conclusively that luxS/smcR quorum sensing endows a global change in gene expression to V. vulnificus.
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PMID:Identification of quorum sensing-related regulons in Vibrio vulnificus by two-dimensional gel electrophoresis and differentially displayed reverse transcriptase PCR. 1750 28

Leishmaniasis is a vector-borne disease caused by the protozoa Leishmania. We have analyzed and compared the sequences of three experimental exoproteomes of Leishmania promastigotes from different species to determine their specific features and to identify new candidate proteins involved in interactions of Leishmania with the host. The exoproteomes differ from the proteomes by a decrease in the average molecular weight per protein, in disordered amino acid residues and in basic proteins. The exoproteome of the visceral species is significantly enriched in sites predicted to be phosphorylated as well as in features frequently associated with molecular interactions (intrinsic disorder, number of disordered binding regions per protein, interaction and/or trafficking motifs) compared to the other species. The visceral species might thus have a larger interaction repertoire with the host than the other species. Less than 10% of the exoproteomes contain heparin-binding and RGD sequences, and ~30% the host targeting signal RXLXE/D/Q. These latter proteins might thus be exported inside the host cell during the intracellular stage of the infection. Furthermore we have identified nine protein families conserved in the three exoproteomes with specific combinations of Pfam domains and selected eleven proteins containing at least three interaction and/or trafficking motifs including two splicing factors, phosphomannomutase, 2,3-bisphosphoglycerate-independent phosphoglycerate mutase, the paraflagellar rod protein-1D and a putative helicase. Their role in host-Leishmania interactions warrants further investigation but the putative ATP-dependent DEAD/H RNA helicase, which contains numerous interaction motifs, a host targeting signal and two disordered regions, is a very promising candidate.
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PMID:Comparative analysis of Leishmania exoproteomes: implication for host-pathogen interactions. 2409 1