Stanford University School of Medicine's Alessandra Chesi and her colleagues define the cellular function of Ypk9 — a non-essential yeast gene whose mutations in its human homolog, ATP13A2/PARK9, have been linked to genetic forms of early onset parkinsonism. In multiple genome-wide screens in yeast, the team deciphered the mechanisms by which Ypk9 "protects cells from manganese toxicity," defining the dependence of non-essential gene-deletion strain phenotypes in the presence of manganese on Ypk9. "These results confirm a role for Ypk9 in manganese homeostasis and illuminates cellular pathways and biological processes in which Ypk9 likely functions," Chesi et al. write in PLoS One.
A team led by researchers at the University of Tübingen in Germany reports in PLoS One this week on "a significant association of FCN2 AGACG haplotype with cutaneous leishmaniasis in a Syrian Arab population." The team says the results of its study on 226 patients with cutaneous leishmaniasis and 286 healthy controls open the door to future studies on the "possible relationships between FCN2 gene polymorphisms with cutaneous leishmaniasis."
Elsewhere in the journal, another team led by investigators at the University of Tübingen shows that "after adjustment for gender and age … SNP rs12603825 revealed significant association with MRI-derived total adipose tissue mass and fasting leptin concentrations, as well as nominal associations with bioelectrical impedance-derived percentage of body fat and clamp-derived insulin sensitivity" in humans. The Tübingen team says the SNP, a common genetic variation in the SERPINF1 locus, "contributes to overall body adiposity, obesity-related insulin resistance, and circulating leptin levels."
Over in PLoS Biology, an international team directed by researchers at Baylor College of Medicine identifies an association between mutations in the mitochondrial methionyl-tRNA synthetase Aats-met — the homologue of human MARS2 — and age-dependent degeneration of photoreceptors, shortened lifespan, and reduced cell proliferation in epithelial tissues in Drosophila. Further, the researchers "identified MARS2 to be mutated in autosomal recessive spastic ataxia with leukoencephalopathy [ARSAL] patients," uncovering "complex rearrangements in the ... gene in all ARSAL patients" studied, they write.
Finally in PLoS Genetics, researchers at the University of Toronto and elsewhere "show that a number of miRNA binding sites display high levels of population differentiation in humans and thus are likely targets of local adaptation," and discuss what they call "the evolutionary plasticity of the miRNA regulatory network in recent human evolution."