In this week's issue of PLoS Genetics, researchers at the University of Georgia report their identification of the DNA-binding domain of a centromere binding protein, CENPC, in maize. They demonstrate that CENPC requires a single-stranded RNA to effectively bind DNA in vitro, and, when absent, the accuracy of CENPC targeting to centromeres is reduced. The authors report that their results support the notion that RNA binding ensures that centromeres are stably inherited, a critical function of the epigenetic determination process.
Also in PLoS Genetics, Neil Morgan and colleagues identify mutations of the gene SLC29A3 as the molecular basis for a familial form of syndromic histiocytosis, confirming a direct link between Faisalabad histiocytosis and Rosai-Dorfman disease, as well as other associated phenotypes. Mutations in SLC29A3, characteristic of these disorders, cause the generation of excessive histiocytes which phagocytose other cells and process antigens. The authors surmise that their discoveries will shed light on the pathophysiology of histiocytic disorders, which have been recognized for nearly a century, but have afforded no disease-specific treatments.
Researchers report a universal trend of reduced mRNA stability near the translation-initiation site in both prokaryotes and eukaryotes in PLoS Computational Biology. Using computational methods to predict the thermodynamic stability of mRNA downstream from the start codon, and information from the complete genomes of 340 species, the team found that, in nearly all species, mRNA stability is reduced near the start codon, and that the reduction of stability correlates with the increasing genomic GC content. While the team did not find a genome-wide trend of reduced mRNA stability near the start codon in birds and mammals, they did find such a reduction in the most GC-rich genes.
Meanwhile, in PLoS One, an international team describes VAV2 and VAV3 as candidate disease genes for spontaneous glaucoma in both mice and humans. VAV2/VAV3-deficient mice show early onset of iridocorneal angle alterations and elevated intraocular pressure with the subsequent loss of retinal gangilion cells and optical nerve head cupping, characteristic of glaucoma, which is the leading cause of blindness in humans. The researchers posit that VAV2/VAV3-deficient mice could serve as a useful model to study the pathogenesis of glaucoma in humans.