Identification and study of a Candida albicans protein homologous to Saccharomyces cerevisiae Ssr1p, an internal cell-wall protein

• Published in: Microbiology (Society for General Microbiology) 2003-08, Vol.149 (8), p.2137-2145
• Main Authors: Garcera, Ana, Martinez, Ana Isabel, Castillo, Luis, Elorza, M. Victoria, Sentandreu, Rafael, Valentin, Eulogio
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Base Sequence; beta -Glucan; Biological and medical sciences; Candida albicans; Candida albicans - genetics; Cell Wall - metabolism; Cloning, Molecular; DNA, Fungal - genetics; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Gene Deletion; Gene Expression; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Microbiology; Molecular Sequence Data; Mycology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins - genetics; Sequence Homology, Amino Acid; Species Specificity; Ssr1 protein; zymolyase
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.26301-0

Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain Correspondence Eulogio Valentin Eulogio.Valentin{at}uv.es After screening of a Candida albicans genome database, the product of an ORF (IPF 3054) that has 62 % homology with Saccharomyces cerevisiae Ssr1p, an internal cell-wall protein, was identified and named CaSsr1p. The deduced amino acid sequence shows that CaSsr1p contains an N-terminal hydrophobic signal peptide, is rich in Ser and Thr amino acids and has a potential glycosylphosphatidylinositol-attachment signal. CaSsr1p is released following degradation of isolated cell walls by zymolyase (mainly a 1,3- -glucanase) and therefore seems to be covalently linked to the -glucan of the cell walls. Both disruption and overexpression of the CaSSR1 gene caused an increased sensitivity to calcofluor white, Congo red and zymolyase digestion. These results suggest that CaSsr1p has a structural role associated with the cell-wall -glucan. Abbreviations: CR, Congo red; CW, calcofluor white; GPI, glycosylphosphatidylinositol; IPF, individual protein file A table showing putative GPI-proteins in Candida albicans can be found in Microbiology Online.