Document Detail


Rap1 in Candida albicans: an unusual structural organization and a critical function in suppressing telomere recombination.
MedLine Citation:
PMID:  20008550     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Rap1 (repressor activator protein 1) is a conserved multifunctional protein initially identified as a transcriptional regulator of ribosomal protein genes in Saccharomyces cerevisiae but subsequently shown to play diverse functions at multiple chromosomal loci, including telomeres. The function of Rap1 appears to be evolutionarily plastic, especially in the budding yeast lineages. We report here our biochemical and molecular genetic characterizations of Candida albicans Rap1, which exhibits an unusual, miniaturized domain organization in comparison to the S. cerevisiae homologue. We show that in contrast to S. cerevisiae, C. albicans RAP1 is not essential for cell viability but is critical for maintaining normal telomere length and structure. The rap1 null mutant exhibits drastic telomere-length dysregulation and accumulates high levels of telomere circles, which can be largely attributed to aberrant recombination activities at telomeres. Analysis of combination mutants indicates that Rap1 and other telomere proteins mediate overlapping but nonredundant roles in telomere protection. Consistent with the telomere phenotypes of the mutant, C. albicans Rap1 is localized to telomeres in vivo and recognizes the unusual telomere repeat unit with high affinity and sequence specificity in vitro. The DNA-binding Myb domain of C. albicans Rap1 is sufficient to suppress most of the telomere aberrations observed in the null mutant. Notably, we were unable to detect specific binding of C. albicans Rap1 to gene promoters in vivo or in vitro, suggesting that its functions are more circumscribed in this organism. Our findings provide insights on the evolution and mechanistic plasticity of a widely conserved and functionally critical telomere component.
Authors:
Eun Young Yu; Wei-Feng Yen; Olga Steinberg-Neifach; Neal F Lue
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2009-12-14
Journal Detail:
Title:  Molecular and cellular biology     Volume:  30     ISSN:  1098-5549     ISO Abbreviation:  Mol. Cell. Biol.     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-02-12     Completed Date:  2010-03-26     Revised Date:  2010-09-02    
Medline Journal Info:
Nlm Unique ID:  8109087     Medline TA:  Mol Cell Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1254-68     Citation Subset:  IM    
Affiliation:
Department of Microbiology and Immunology, W. R. Hearst Microbiology Research Center, Weill Medical College of Cornell University, 1300 York Ave., New York, New York 10021, USA.
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MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Base Sequence
Binding Sites / genetics
Candida albicans / genetics*,  growth & development,  metabolism*
DNA Primers / genetics
DNA, Fungal / genetics,  metabolism
Evolution, Molecular
Fungal Proteins / chemistry*,  genetics,  metabolism*
Genes, Fungal
Models, Biological
Molecular Sequence Data
Mutation
Phenotype
Protein Structure, Tertiary
Recombination, Genetic*
Saccharomyces cerevisiae Proteins / chemistry,  genetics
Sequence Homology, Amino Acid
Sequence Homology, Nucleic Acid
Species Specificity
Telomere / genetics*,  metabolism*
Telomere-Binding Proteins / chemistry*,  genetics,  metabolism*
Transcription Factors / chemistry*,  genetics,  metabolism*
Grant Support
ID/Acronym/Agency:
GM-069507/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/DNA Primers; 0/DNA, Fungal; 0/Fungal Proteins; 0/RAP1 protein, Candida albicans; 0/RAP1 protein, S cerevisiae; 0/Saccharomyces cerevisiae Proteins; 0/Telomere-Binding Proteins; 0/Transcription Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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