The fine structure of isolated chitin synthetase (UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamido-deoxyglucosyltransferase; EC 2-4-1-16) particles (chitosomes) from Mucor rouxii and the elaboration microfibrils were studied by electron microscopy. Chitosomes are spheroidal, but often polymorphic, structures, mostly 40-70 nm in diameter. Their appearance after negative staining varies. Some reveal internal granular enclosed a shell measuring 6-12 thick; others do not show have...

We have devised a convenient procedure to induce the yeast-to-mycelium transition of Yarrowia lipolytica in conditions which avoid occurrence reverse process during period study. Yeast cells late exponential phase were resuspended water and cooled down 4 °C for at least 15 min, then heat-shocked by inoculation into pre-warmed (30 °C) medium containing N-acetyl-d-glucosamine. Under these conditions, yeast developed large branching filaments continued elongating more than 24 h. Further,...

Summary: The gene encoding ornithine decarboxylase (ODC) from Ustilago maydis was cloned. A conserved PCR product amplified U. DNA synthesized and used to screen a genomic library of the fungus. Alignment its deduced protein sequence with those other cloned ODCs showed high degree homology. Gene replacement obtained by removal central part insertion hygromycin resistance cassette. null mutant thus displayed no ODC activity behaved as polyamine auxotroph. This result is evidence that single...

Transcriptomic and biochemical analyses of the experimental pathosystem constituted by Ustilago maydis Arabidopsis thaliana were performed. Haploid or diploid strains U. inoculated in A. plantlets grew on surface within plant tissues form mycelium, inducing chlorosis, anthocyanin formation, malformations, necrosis adventitious roots development, but not teliospores. Symptoms more severe plants with haploid strain which vigorously than strain. RNA extracted at different times post-infection...

The cellular site of initial glycosylation proteins from Saccharomyces cerevisiae has been studied. Short pulses [U-14C]mannose label the ribosomal fraction yeast. Most was associated with polysomes; monosomes contained only a small amount radioactivity. All radioactivity present in polysomal accounted by mannose and smaller amounts glucose glucosamine. Puromycin treatment detached more than 50% polysomes at pH 10.0 also caused release These results indicate that sugar binding occurs while...

ABSTRACT Candida albicans , the most common fungal pathogen, regulates its cellular morphology in response to environmental conditions. The ODC gene, which encodes ornithine decarboxylase, a key enzyme polyamine biosynthesis, was isolated and disrupted. Homozygous null mutants behaved as auxotrophs grew exclusively yeast form at low levels (0.01 mM putrescine) under all conditions tested. An increase concentration (10 restored capacity switch from filamentous form. strain with deletion...

ABSTRACT The experimental infection of Arabidopsis thaliana by the maize phytopathogenic hemibasidiomycete Ustilago maydis under axenic conditions is described. When plantlets were inoculated with mixtures compatible haploids, fungus was able to grow on plant surface seedlings in form white mycelium and invade tissues, probably penetrating through stomata; however, it did not teliospores. Symptoms disease increased anthocyanin formation, development chlorosis, formation secondary roots,...

We have advanced the hypothesis that polyamines affect DNA methylation and thus promote expression of developmentally controlled genes. demonstrate activity cytosine‐DNA methyltransferases Hpa II, Hha I, Hae III Sss I is inhibited by physiological concentrations polyamines. On other hand, adenine‐DNA methyltransferase Eco RI, restriction enzymes insensitive to polyamine up 40 mM. Our results indicate effect on methyltranferases rather selective suggest a possible mode action in vivo.

The proteolytic system of the phytopathogenic and dimorphic fungus Ustilago maydis is not known. In this work, we report presence at least four proteases from two haploid strains U. maydis. Activities proteinases pumA pumB, aminopeptidase pumAPE, dipeptidylaminopeptidase pumDAP were measured under several nutritional morphological conditions, including yeast-mycelium transition. activity was found in intracellular extracellular fractions, pumAi pumAe, respectively. latter detected only...

Yarrowia lipolytica is an ascomycetous dimorphic yeast with immense potential for industrial applications, including bioremediation of crude oil-contaminated environments. It has been shown that a marine isolate Y. (var. indica) significant capacity to degrade fatty acids and alkanes, when in its morphology. also demonstrated polyamines play important role the yeast-to-mycelium transition different strains are unable utilize those carbon sources. To determine on their oils hydrocarbons,...

A method was devised for the isolation of yeast monomorphic (LEV) mutants Candida albicans. By this procedure, about 20 stable yeast-like were isolated after mutagenesis with ethyl methane sulfonate. The growth rate in different carbon sources, both fermentable and not, indistinguishable from that parental strain, but they unable to grow as mycelial forms application any common effective inducers, i.e., heat shock, pH alterations, proline addition, or use GlcNAc source. Studies performed one...