Search results for "albicans"

The Yeast External Invertase as a Reporter to Study Regulation ofCandida Albicans Promoter Sequences inSaccharomyces Cerevisiae

2008

Genomic response programs of Candida albicans following protoplasting and regeneration

2005

Transcription profiling of Candida albicans cells responding to the elimination of the wall (protoplasts) and posterior regeneration was explored. DNA microarrays were used to measure changes in the expression of 6039 genes, and the upregulated genes during regeneration at 28 degrees C were assigned to fourteen categories. A total of 407 genes were upregulated during the process, of which 144 reached a maximum after 1 h. MKC1, a gene encoding a member of the regulatory pathway involved in cell wall integrity was overexpressed. Time-dependent expression divided the genes into 40 clusters. Clusters 1-19 were highly expressed initially (time 0) and downregulated following incubation, whereas t…

A Candida albicans 37 kDa polypeptide with homology to the laminin receptor is a component of the translational machinery.

1998

A cDNA encoding a 37 kDa protein was isolated from an expression library using antibodies raised against mycelial cell walls fromCandida albicans.The 37 kDa protein has over 60% sequence identity with the 37 kDa laminin-binding protein (LBP) from humans and over 80% identity with the Yst proteins ofSaccharomyces cerevisiae. TheC. albicansprotein was named CaYst1. It was found in membrane and ribosome fractions but surprisingly, was not found in cell walls. Unlike the human LBP, CaYst1p does not bind laminin. These data indicate that CaYst1p is not a cell-surface receptor for laminin as has been proposed for the human LBP. Instead, like theS. cerevisiaeYst proteins, it appears to be a riboso…

The Candida albicans UBI3 gene encoding a hybrid ubiquitin fusion protein involved in ribosome biogenesis is essential for growth.

2003

We have constructed a conditional null mutant Candida albicans strain for the UBI3 gene which encodes a ubiquitin fusion protein involved in ribosome biogenesis. A one-step gene disruption procedure, using the plasmid pCaDis, was designed to place the second copy of the UBI3 gene under the control of the tightly regulated MET3 promoter in a C. albicans heterozygous strain (UBI3/Deltaubi3::hisG), previously isolated in the first step of the ura-blaster protocol. Analysis of the conditional null mutant in repressing and inducing conditions indicates that UBI3 is an essential gene whose expression is required for growth of C. albicans.

The ATC1 gene encodes a cell wall-linked acid trehalase required for growth on trehalose in Candida albicans.

2004

After screening a Candida albicans genome data base, the product of an open reading frame (IPF 19760/CA2574) with 41% identity to Saccharomyces cerevisiae vacuolar acid trehalase (Ath1p) was identified and named Atc1p. The deduced amino acid sequence shows that Atc1p contains an N-terminal hydrophobic signal peptide and 20 potential sites for N-glycosylation. C. albicans homozygous mutants that lack acid trehalase activity were constructed by gene disruption at the two ATC chromosomal alleles. Analysis of these null mutants shows that Atc1p is localized in the cell wall and is required for growth on trehalose as a carbon source. An Atc1p endowed with acid trehalase activity was obtained by …

Role of Pir1 in the construction of the Candida albicans cell wall

2004

Searches in a Candida albicans database (http://genolist.pasteur.fr/CandidaDB/) identified two Individual Protein Files (IPF 15363 and 19968) whose deduced amino acid sequences showed 42 % and 45 % homology with Saccharomyces cerevisiae Pir4. The two DNA sequences are alleles of the same gene (CaPIR1) but IPF 19968 has a deletion of 117 bases. IPF 19968 encodes a putative polypeptide of 364 aa, which is highly O-glycosylated and has an N-mannosylated chain, four cysteine residues and seven repeats. Both alleles are expressed under different growth conditions and during wall construction by regenerating protoplasts. The heterozygous mutant cells are elongated, form clumps of several cells an…

Depletion of polyubiquitin encoded by the UBI4 gene confers pleiotropic phenotype to Candida albicans cells.

2003

We have studied the roles of polyubiquitin in Candida albicans physiology. Heterologous expression of the C. albicans polyubiquitin (UBI4) gene in a ubi4 Saccharomyces cerevisiae strain suppressed the mutant phenotype (hypersensitivity to heat shock). A heterozygous strain UBI4/Deltaubi4::hisG, obtained following the ura-blaster procedure, was used to construct a conditional mutant using a pCaDis derivative plasmid. By serendipity we isolated the UBI4 conditional mutant as well as a UBI4 mutant containing a non-functional MET3 promoter. Depletion of polyubiquitin conferred pleiotropic effects to mutant cells: (i) a limited increased sensitivity to mild heat shock; (ii) increased formation o…

Molecular cloning and characterization of a Candida albicans gene coding for cytochrome c haem lyase and a cell wall-related protein.

1998

Immunoscreening of a Candida albicans cDNA library with a monoclonal antibody (mAb 4C12) recognizing an epitope present in high-molecular-weight mannoprotein (HMWM) components specific for the mycelial cell walls (a 180 kDa component and a polydispersed 260 kDa species) resulted in the isolation of the gene CaCYC3 encoding for cytochrome c haem lyase (CCHL). The CaCYC3 gene was transcribed preferentially in mycelial cells in which two mRNA transcripts of 0.8 and 1 kb were found. The nucleotide and the deduced amino acid sequences of this gene displayed 45% homology and 46% identity, respectively, to the Saccharomyces cerevisiae CYC3 gene and shared common features with other reported genes …

Starvation and temperature upshift cause an increase in the enzymatically active cell wall-associated glyceraldehyde-3-phosphate dehydrogenase protei…

2003

The cell wall-associated glyceraldehyde-3-phosphate dehydrogenase (cwGAPDH) activity in Saccharomyces cerevisiae increases (two- to 10-fold, depending on the strain) in response to starvation and temperature upshift. Assays using transformants carrying pTDH, a yeast centromer derivative plasmid containing the Candida albicans TDH3 gene (encoding GAPDH) fused in frame with the yeast SUC2-coding region for internal invertase, showed that starvation and/or temperature upshift result in a similar increase in both cwGAPDH and cell wall-associated invertase activities. In addition, this incorporation of GAPDH protein into the cell wall in response to stress does not require (i) de novo protein sy…

In vitro assessment of the antifungal effects of neem powder added to polymethyl methacrylate denture base material

2018

Background Denture with antimicrobial activities is desirable to prevent Candida albican adhesion subsequently decreasing the susceptibility of denture stomatitis incidence. Azadirachta Indica, commonly known as Neem powder has antimicrobial effect but the effect of its addition to acrylic denture base on C. albicans adhesion has not been investigated. The aim of this study was determine whether adding neem powder to acrylic denture base materials could reduce Candida albicansadhesion. Material and methods One hundred and twenty acrylic resin denture specimens were fabricated and divided into heat-polymerized (n=60) and auto-polymerized (n=60) groups. Each group was further divided into 6 g…