Disease relevance of SSL2

• RAD25 (SSL2), the yeast homolog of the human xeroderma pigmentosum group B DNA repair gene, is essential for viability [1].

High impact information on SSL2

• Factor b interacts specifically with another DNA repair protein, SSL2 [2].
• However, the SSL2 suppressor gene does not restore HIS4 expression by removal of the stem-loop from DNA or the mRNA [3].
• We propose that SSL2 and ERCC-3 may have two functions, one defined by a UV repair defect, and a second essential function that is related to gene expression [3].
• The RAD25 protein shows remarkable homology to the protein encoded by the human nucleotide-excision-repair gene XPB (ERCC3), mutations in which cause the cancer-prone disease xeroderma pigmentosum and also Cockayne's syndrome [4].
• The RAD25 gene of Saccharomyces cerevisiae functions in nucleotide excision repair of ultraviolet-damaged DNA and is also required for cell viability [4].

Biological context of SSL2

• We present genetic evidence suggesting that the DNA-repair function of SSL2 protein is not dependent on its essential function [5].
• It was established that the uvs112 mutation caused a 2.5-fold reduction in the number of recombinants produced by conversion and also significantly increased the frequency of mitotic crossing-over in interplasmid recombination [6].
• Tetrad analysis placed the UVS112 gene on the left arm of chromosome IX, approximately 20 cM from HIS5 [6].
• The SSL2 protein has a high degree of amino acid sequence identity to the protein encoded by the human ERCC3 gene (Gulyas, K. D., and Donahue, T. F. (1992) Cell 69, 1031-0142) [7].
• We examined several yeast strains with different mutations in the essential SSL2 (Suppressor of Stem Loop, also called RAD25) gene for their ability to remove cyclobutane pyrimidine dimers from expressed genes, and from the genome overall [7].

Associations of SSL2 with chemical compounds

• DNA unwinding was probed with an in vivo permanganate reactivity assay, in a temperature-sensitive mutant of RAD25 [8].
• However, the role of Ssl2 (Rad25) in cisplatin sensitivity has not been examined [9].

Physical interactions of SSL2

• RAD3 protein binds directly to both SSL2 protein and SSL1 protein in vitro [5].

Regulatory relationships of SSL2

• Multiple mutant alleles of SSL2 exhibited a pronounced growth defect when co-expressed with a mutant allele of Hsp90 [10].

Other interactions of SSL2

• The RAD3 and SSL2 gene products are essential proteins that are also required for the nucleotide excision repair pathway [5].
• In Schizosaccharomyces pombe, the BMH homologues (RAD24 and RAD25) are essential for cell cycle control after DNA damage and deletion of both genes renders the cell inviable [11].
• The Rad25 protein in yeast is a DNA helicase and a subunit of the general transcription factor TFIIH [12].

References