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

Abstract

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 of colony morphology variants; and (iii) induction of hyphal and pseudohypal development. These results indicate that polyubiquitin in C. albicans is involved in the negative control of switching, as well as in maintaining the yeast cell morphology, probably by silencing mechanisms triggering the hyphal and pseudohyphal development in the absence of environmental inducers.

• Authors: Patricia Roig, Daniel Gozalbo
• Journal: Fungal genetics and biology : FG & B (Fungal Genet Biol) Vol. 39 Issue 1 Pg. 70-81 (Jun 2003) ISSN: 1087-1845 [Print] United States
• PMID: 12742065 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Saccharomyces cerevisiae Proteins
• UBI4 protein, S cerevisiae
• Ubiquitin C
• Polyubiquitin

Topics

• Candida albicans (cytology, genetics, metabolism)
• Cloning, Molecular
• Gene Deletion
• Heat-Shock Response
• Hyphae (cytology, growth & development)
• Morphogenesis
• Phenotype
• Polyubiquitin (deficiency, genetics)
• Promoter Regions, Genetic
• Saccharomyces cerevisiae Proteins (biosynthesis, genetics)
• Transformation, Genetic
• Ubiquitin C (biosynthesis, genetics)