Role of Lipid in Hemagglutination by Candida albicans and Saccharomyces cerevisiae

1957 ◽  
Vol 94 (2) ◽  
pp. 279-283 ◽  
Author(s):  
R. A. Vogel
1998 ◽  
Vol 180 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Laura Popolo ◽  
Marina Vai

ABSTRACT Analysis of Candida albicans cells using antibodies directed against Gas1p/Ggp1p, Saccharomyces cerevisiaehomolog of Phr1p, revealed that Phr1p is a glycoprotein of about 88 kDa whose accumulation increases with the rise of external pH. This polypeptide is present both in the yeast form and during germ tube induction. In the Phr1− cells at pH 8 the solubility of glucans in alkali is greatly affected. In the parental strain the alkali-soluble/-insoluble glucan ratio shows a 50% decrease at pH 8 with respect to pH 4.5, whereas in the null mutant it is unchanged, indicating the lack of a polymer cross-linker activity induced by the rise of pH. The mutant has a sixfold increase in chitin level and is hypersensitive to calcofluor. Consistently with a role of chitin in strengthening the cell wall, Phr1− cells are more sensitive to nikkomycin Z than the parental strain.


2004 ◽  
Vol 3 (3) ◽  
pp. 724-734 ◽  
Author(s):  
Alysia L. vandenBerg ◽  
Ashraf S. Ibrahim ◽  
John E. Edwards ◽  
Kurt A. Toenjes ◽  
Douglas I. Johnson

ABSTRACT The yeast Candida albicans is a major opportunistic pathogen of immunocompromised individuals. It can grow in several distinct morphological states, including budded and hyphal forms, and the ability to make the dynamic transition between these forms is strongly correlated with virulence. Recent studies implicating the Cdc42p GTPase in hypha formation relied on cdc42 mutations that affected the mitotic functions of the protein, thereby precluding any substantive conclusions about the specific role of Cdc42p in the budded-to-hypha-form transition and virulence. Therefore, we took advantage of several Saccharomyces cerevisiae cdc42 mutants that separated Cdc42p's mitotic functions away from its role in filamentous growth. The homologous cdc42-S26I, cdc42-E100G, and cdc42-S158T mutations in C. albicans Cdc42p caused a dramatic defect in the budded-to-hypha-form transition in response to various hypha-inducing signals without affecting normal budded growth, strongly supporting the conclusion that Cdc42p has an integral function in orchestrating the morphological transition in C. albicans. In addition, the cdc42-S26I and cdc42-E100G mutants demonstrated a reduced ability to damage endothelial cells, a process that is strongly correlated to virulence. The three mutants also had reduced expression of several hypha-specific genes, including those under the regulation of the Efg1p transcription factor. These data indicate that Cdc42p-dependent signaling pathways regulate the budded-to-hypha-form transition and the expression of hypha-specific genes.


Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 2912-2919 ◽  
Author(s):  
Yong Liang ◽  
Dongsheng Wei ◽  
Hui Wang ◽  
Ning Xu ◽  
Biao Zhang ◽  
...  

The ability of Candida albicans to act as an opportunistic fungal pathogen is linked to its ability to switch among different morphological forms. This conversion is an important feature of C. albicans and is correlated with its pathogenesis. Many conserved positive and negative transcription factors regulate morphogenetic transition of C. albicans. Here, we show the results of functional analysis of CaAFT2, which is an orthologue of the Saccharomyces cerevisiae AFT2 gene. We have cloned CaAFT2 which has an ability to complement the S. cerevisiae aft1Δ mutant strain growth defect. Interestingly, although disruption of the AFT2 gene did not affect cell growth in solid and liquid iron-limited conditions, the cell surface ferric reductase activity was significantly decreased. Importantly, deletion of AFT2 in C. albicans led to growth of a smooth colony with no peripheral hyphae. Moreover, virulence of an aft2Δ/aft2Δ mutant was markedly attenuated in a mouse model. Our results suggest that CaAft2p represents a novel activator and that it functions in ferric reductase activity, morphogenesis and virulence in C. albicans.


Author(s):  
Linru Huang ◽  
Zhijia Fang ◽  
Jian Gao ◽  
Jingwen Wang ◽  
Yongbin Li ◽  
...  

Author(s):  
Piero Sciavilla ◽  
Francesco Strati ◽  
Monica Di Paola ◽  
Monica Modesto ◽  
Francesco Vitali ◽  
...  

Abstract Studies so far conducted on irritable bowel syndrome (IBS) have been focused mainly on the role of gut bacterial dysbiosis in modulating the intestinal permeability, inflammation, and motility, with consequences on the quality of life. Limited evidences showed a potential involvement of gut fungal communities. Here, the gut bacterial and fungal microbiota of a cohort of IBS patients have been characterized and compared with that of healthy subjects (HS). The IBS microbial community structure differed significantly compared to HS. In particular, we observed an enrichment of bacterial taxa involved in gut inflammation, such as Enterobacteriaceae, Streptococcus, Fusobacteria, Gemella, and Rothia, as well as depletion of health-promoting bacterial genera, such as Roseburia and Faecalibacterium. Gut microbial profiles in IBS patients differed also in accordance with constipation. Sequence analysis of the gut mycobiota showed enrichment of Saccharomycetes in IBS. Culturomics analysis of fungal isolates from feces showed enrichment of Candida spp. displaying from IBS a clonal expansion and a distinct genotypic profiles and different phenotypical features when compared to HS of Candida albicans isolates. Alongside the well-characterized gut bacterial dysbiosis in IBS, this study shed light on a yet poorly explored fungal component of the intestinal ecosystem, the gut mycobiota. Our results showed a differential fungal community in IBS compared to HS, suggesting potential for new insights on the involvement of the gut mycobiota in IBS. Key points • Comparison of gut microbiota and mycobiota between IBS and healthy subjects • Investigation of cultivable fungi in IBS and healthy subjects • Candida albicans isolates result more virulent in IBS subjects compared to healthy subjects


Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1261-1272 ◽  
Author(s):  
Laura Salem ◽  
Natalie Walter ◽  
Robert Malone

Abstract REC104 is a gene required for the initiation of meiotic recombination in Saccharomyces cerevisiae. To better understand the role of REC104 in meiosis, we used an in vitro mutagenesis technique to create a set of temperature-conditional mutations in REC104 and used one ts allele (rec104-8) in a screen for highcopy suppressors. An increased dosage of the early exchange gene REC102 was found to suppress the conditional recombinational reduction in rec104-8 as well as in several other conditional rec104 alleles. However, no suppression was observed for a null allele of REC104, indicating that the suppression by REC102 is not “bypass” suppression. Overexpression of the early meiotic genes REC114, RAD50, HOP1, and RED1 fails to suppress any of the rec104 conditional alleles, indicating that the suppression might be specific to REC102.


2021 ◽  
Vol 150 ◽  
pp. 104689
Author(s):  
José Marcos Sanches ◽  
Luana Rossato ◽  
Izabella Lice ◽  
Anna Maria Alves de Piloto Fernandes ◽  
Gustavo Henrique Bueno Duarte ◽  
...  

2002 ◽  
Vol 1 (3) ◽  
pp. 448-457 ◽  
Author(s):  
Toshimitsu Takagi ◽  
Eun-Jung Cho ◽  
Rozmin T. K. Janoo ◽  
Vladimir Polodny ◽  
Yasutaka Takase ◽  
...  

ABSTRACT The Saccharomyces cerevisiae mRNA capping enzyme consists of two subunits: an RNA 5′-triphosphatase (RTPase) and GTP::mRNA guanylyltransferase (GTase). The GTase subunit (Ceg1) binds to the phosphorylated carboxyl-terminal domain of the largest subunit (CTD-P) of RNA polymerase II (pol II), coupling capping with transcription. Ceg1 bound to the CTD-P is inactive unless allosterically activated by interaction with the RTPase subunit (Cet1). For purposes of comparison, we characterize here the related GTases and RTPases from the yeasts Schizosaccharomyces pombe and Candida albicans. Surprisingly, the S. pombe capping enzyme subunits do not interact with each other. Both can independently interact with CTD-P of pol II, and the GTase is not repressed by CTD-P binding. The S. pombe RTPase gene (pct1 +) is essential for viability. Pct1 can replace the S. cerevisiae RTPase when GTase activity is supplied by the S. pombe or mouse enzymes but not by the S. cerevisiae GTase. The C. albicans capping enzyme subunits do interact with each other. However, this interaction is not essential in vivo. Our results reveal an unexpected diversity among the fungal capping machineries.


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