In a paper published online in advance in Nature this week, researchers at the University of Cologne report their use of Saccharomyces cerevisiae OAZ1 "to dissect the enigmatic mechanism underlying polyamine regulation of RFS," or ribosomal frameshifting. "In contrast with previous assumptions, we report here that the nascent antizyme polypeptide is the relevant polyamine sensor that operates in cis to negatively regulate upstream RFS on the polysomes, where its own mRNA is being translated," the authors write, adding that their study "reveals a novel autoregulatory mechanism in which binding of a small metabolite to a nascent sensor protein stimulates the latter’s synthesis co-translationally."
Elsewhere in Nature's advance online publications, investigators at the Salk Institute for Biological Sciences in La Jolla, Calif., and at the Netherlands Cancer Institute show that "loss of Brca1 in mice results in transcriptional de-repression of the tandemly repeated satellite DNA," and is further "accompanied by a reduction of condensed DNA regions in the genome and loss of ubiquitylation of histone H2A at satellite repeats." Overall, the authors say that BRCA1's role in "maintaining global heterochromatin integrity accounts for many of its tumor suppressor functions."
In another paper published online in advance, an international team led by investigators at Auburn University in Alabama use transcriptome and genome data from all major lineages of Mollusca — except Monoplacophora — in a phylogenetic analysis, the results of which lend support to "the Aculifera hypothesis, placing Polyplacophora (chitons) in a clade with a monophyletic Aplacophora (worm-like mollusks)," the authors write.
Researchers at Yale Univeristy this week present their transcriptomic analysis of avian wing digits, which they say "reveals conserved and derived digit identities in birds." The team says its data for posterior bird digits "show a higher degree of differentiation among forelimb digits compared with hindlimb digits," and overall, they "indicate that the posterior wing digits have unique identities contrary to any model of avian digit identity proposed so far."