A G-protein α subunit from asexual Candida albicans functions in the mating signal transduction pathway of Saccharomyces cerevisiae and is regulated by the a1-α2 repressor

Sadhu, C., Hoekstra, D., McEachern, M. J., Reed, S. I., Hicks, J. B. (1992) A G-protein α subunit from asexual Candida albicans functions in the mating signal transduction pathway of Saccharomyces cerevisiae and is regulated by the a1-α2 repressor. Molecular and Cellular Biology, 12 (5). pp. 1977-1985. ISSN 02707306 (ISSN)

URL: http://www.ncbi.nlm.nih.gov/pubmed/1569935
DOI: 10.1128/MCB.12.5.1977


We have isolated a gene, designated CAG1, from Candida albicans by using the G-protein α-subunit clone SCG1 of Saccharomyces cerevisiae as a probe. Amino acid sequence comparison revealed that CAG1 is more homologous to SCG1 than to any other G protein reported so far. Homology between CAG1 and SCG1 not only includes the conserved guanine nucleotide binding domains but also spans the normally variable regions which are thought to be involved in interaction with the components of the specific signal transduction pathway. Furthermore, CAG1 contains a central domain, previously found only in SCG1. cag1 null mutants of C. albicans created by gene disruption produced no readily detectable phenotype. The C. albicans CAG1 gene complemented both the growth and mating defects of S. cerevisiae scg1 null mutants when carried on either a low- or high-copy-number plasmid. In diploid C. albicans, the CAG1 transcript was readily detectable in mycelial and yeast cells of both the white and opaque forms. However, the CAG1-specific transcript in S. cerevisiae transformants containing the C. albicans CAG1 gene was observed only in haploid cells. This transcription pattern matches that of SCG1 in S. cerevisiae and is caused by a1-α2-mediated repression in diploid cells. That is, CAG1 behaves as a haploid-specific gene in S. cerevisiae, subject to control by the a1-α2 mating-type regulation pathway. We infer from these results that C. albicans may have a signal transduction system analogous to that controlling mating type in S. cerevisiae or possibly even a sexual pathway that has so far remained undetected.

Item Type: Paper
Uncontrolled Keywords: protein g protein subunit amino acid sequence article candida albicans clone gene location mating type nonhuman northern blotting priority journal protein analysis protein domain pulsed field gel electrophoresis repressor gene saccharomyces cerevisiae sequence homology signal transduction transcription regulation Base Sequence Binding Sites Comparative Study Crosses, Genetic Fungal Proteins Genes, Structural, Fungal GTP-Binding Proteins Haploidy Macromolecular Systems Molecular Sequence Data Mutagenesis, Insertional Plasmids Repressor Proteins Restriction Mapping Sequence Homology, Nucleic Acid Support, Non-U.S. Gov't Support, U.S. Gov't, P.H.S. Transcription, Genetic
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > G protein
organism description > yeast
CSHL Authors:
Communities: CSHL labs > Hicks lab
Depositing User: Matt Covey
Date: 1992
Date Deposited: 09 Aug 2013 20:55
Last Modified: 12 Aug 2013 15:06
Related URLs:
URI: https://repository.cshl.edu/id/eprint/28523

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