In the early, online edition of the Proceedings of the National Academy of Sciences, researchers from South Korea, the US, and China characterize genes involved in histone deacetylation in the model plant Arabidopsis thaliana. Using a combination of RNA sequencing, chromatin immunoprecipitation sequencing, quantitative RT-PCT, Western blot assays, and other approaches, the team identified interactions between the POWERDRESS protein and the histone deacetylase enzyme HDA9 that remove acetylation marks from histone H3 and influence flowering time and other Arabidopsis features. The investigators profiled acetylation and expression patterns in the absence of the genes to further tease apart these interactions and their consequences.
A team from Tsinghua University in China explore the effects of pathogenic presenilin-1 mutations, focusing on 138 mutations with potential ties to Alzheimer's disease in humans. For their analyses, the researchers systematically studied each of the presenilin-1 variations in a human cell line, looking at their relationship to beta-amyloid peptides produced by gamma-secretase enzyme cleavage and the ratios of beta-amyloid peptides of different lengths. "The comprehensive characterization of pathogenic [presenilin-1] mutations serves as a valuable resource for the analysis of gamma-secretase activities and [Alzheimer's disease] pathogenesis," they write.
Finally, researchers from the UK, US, and elsewhere report on results of a genome-wide association meta-analysis aimed at uncovering genetic factors that influence alcohol consumption. Using genotyping data for almost 70,500 individuals of European ancestry and information on individuals' average alcohol intake per day, the team narrowed in on suspicious SNPs that were subsequently tested in more than 35,400 additional individuals. The search led to variants in and around the KLB gene — a candidate gene that was tested in more detail in mouse models missing the gene.