In PLoS Biology this week, collaborating researchers in Seattle and Japan investigate the role of PARP-1 in the repair of DNA lesions. Their study shows that PARP-1 deficiency results in a reduction in gene conversions and enhances repair of AID-induced lesions. "This revealed a requirement for the previously uncharacterized BRCT domain of PARP-1 to reconstitute both gene conversion and a normal rate of somatic mutation at Ig genes, while being dispensable for the high-fidelity base excision repair," the team writes. "From these data we conclude that the BRCT domain of PARP-1 is required to initiate a significant proportion of the mutagenic repair specific to diversifying antibody genes."
In PLoS Genetics this week, researchers from the University of Michigan elucidate the role of Structural Maintenance of Chromosomes proteins in germ cell genomic stability. They found that SMCs 5 and 6 in Caenorhabditis elegans are required to complete meiotic homologous recombination repair. "Based on these findings, we propose that the C. elegans SMC-5/6 proteins are required in meiosis for the processing of homolog-independent, presumably sister-chromatid-mediated, recombination repair," the researchers write. "Together, these results demonstrate that the successful completion of homolog-independent recombination is crucial for germ cell genomic stability."
In PLoS One, a team from Duke University Medical Center demonstrates that the dsRNA binding protein 76 shows distinct tissue type-specific subcellular distribution in a normal human central nervous system and in malignant glial brain tumors. "Altered subcellular localization and isoform distribution in malignant glioma indicate that tumor-specific changes in DRBP76-related gene products and their regulatory functions may contribute to the formation and/or maintenance of these tumors," the team writes. The function role of DRBP76 in co- or post-transcriptional gene regulation could be a contributing factor in the neoplastic phenotype, the researchers add.
And also in PLoS Genetics this week, an international team of researchers reports its genome-wide association study of serum calcium's association with SNPs in or near the calcium-sensing receptor gene on 3q13. "This genome-wide meta-analysis shows that common CASR variants modulate serum calcium levels in the adult general population, which confirms previous results in some candidate gene studies of the CASR locus," the researchers write, which highlights the key role of CASR in calcium regulation. "Our results show that CASR is a key player in genetic regulation of serum calcium in the adult general population," the team adds.