Histidine kinases keep fungi safe and vigorous.

Signal transduction in human pathogenic fungi, like in other microorganisms, regulates a number of adaptive transcriptional responses to a variety of environmental cues. Among signal relay proteins, sensor, histidine kinase proteins (HK) are auto-phosphorylated upon perception of an environmental cue, and initiate a phosphorelay that results in transcriptional regulation of genes associated with specific stress signals or multiple stress cues. Human pathogenic fungi utilize HK proteins to adapt to stress, grow, sporulate, undergo morphogenesis, mate, sense anti-fungal drugs, and cause disease.

Structural elucidation of the repeat unit in highly branched acidic exopolysaccharides produced by nitrogen fixing Burkholderia.

Burkholderia kururiensis, strain M130, an endophytic diazotrophic bacterium isolated from rice roots, produces acetylated acidic exopolysaccharides which can be separated by anion exchange chromatography. These were characterized by nuclear magnetic resonance spectroscopy, methylation analysis and Smith degradation. The exopolysaccharides eluted with 0.

Alpha-N-acetylglucosamine-linked O-glycans of sialoglycoproteins (Tc-mucins) from Trypanosoma cruzi Colombiana strain.

Trypanosoma cruzi sialoglycoproteins (Tc-mucins) are mucin-like molecules linked to a parasite membrane via a glycosylphosphatidylinositol anchor. We previously determined the structures of Tc-mucin O-glycan domains from several T. cruzi strains and observed significant differences among them.

Goa1p of Candida albicans localizes to the mitochondria during stress and is required for mitochondrial function and virulence.

Using a Tn7 transposon library of Candida albicans, we have identified a mutant that exhibited sensitivity in drop plate assays to oxidants such as menadione and hydrogen peroxide. To verify the role of the mutated gene in stress adaptation, null mutants were constructed and phenotypically characterized. Because of its apparent functions in growth and oxidant adaptation, we have named the gene GOA1.

Heterogeneity in the biosynthesis of mucin O-glycans from Trypanosoma cruzi tulahuen strain with the expression of novel galactofuranosyl-containing oligosaccharides.

Sialoglycoprotein from Trypanosoma cruzi strains participates in important biological functions in which the O-linked glycans play a pivotal role, and their structural diversity may be related to the parasite's virulence pattern. To provide supporting evidence for this idea, we have determined the structure of novel linear and branched alpha-O-GlcNAc-linked oligosaccharides present on the mucins of the T. cruzi Tulahuen strain.