Characterisation of the hSNM1B/Apollo protein in the cellular response to DNA damage in the context of the FA/BRCA pathway

• Applicant: Professor Dr. Ilja Demuth
• Subject Area: Human Genetics
• Term: from 2015 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269195109

We have identified the hSNM1B/Apollo gene based on its similarity to a yeast (S.cerevisiae) DNA-repair gene, PSO2. The cellular phenotype of cultured cells depleted for hSNM1B/Apollo (siRNA) is reminescent to the cellular phenotype of cells from patients affected from recessive inherited disease Fanconi Anemia (FA). We therefore proposed a hSNM1B/Apollo role within the FA/BRCA pathway in the response to DNA damage. Homozygous mutations in 16 different genes can cause FA, whereas heterozygous mutations in some of these genes are associated with an increased risc to develop cancer (e.g. BRCA2).Recently we were able to establish a direct link between hSNM1B/Apollo and the FA/BRCA pathway: hSNM1B/Apollo interacts physically with one of the known FA proteins, FANCP/SLX4. Here we would like to further narrow down the protein domains in both proteins relevant for this interaction and characterize them in hSNM1B/Apollo null mutant cell lines. Another important aspect of this project will be the analysis of the impact of different SNPs located at the hSNM1B/Apollo locus and known to influence the amount of cellular hSNM1B/Apollo-mRNA on the cellular DNA damage response phenotype. Lymphoblastoid cells of different SNP genotypes will be analysed with respect to mutagen sensitivity and phosphorylation status of relevant proteins (ATM, SMC1) in response to DNA damage.

• DFG Programme: Research Grants