In a Nucleic Acids Research paper published online in advance this week, researchers at the University of Wisconsin-Madison show that "automethylation of CARM1 allows coupling of transcription and mRNA splicing," which they determined as a result of their top-down mass spectrometry-based investigations of post-translational modifications to the histone arginine methyltransferase. In mice, CARM1, which is a "co-activator for many transcription factors," the authors write, is dimethylated both in vivo and in vitro by an automethylation mechanism. When the Wisconsin team disturbed auto-methylation through targeted mutation, CARM1-activated transcription and pre-mRNA splicing were both impaired. "These results strongly imply that automethylation of CARM1 provides a direct link to couple transcription and pre-mRNA splicing in a manner differing from the other steroid receptor co-activators," the authors conclude.
Researchers at Germany's University of Potsdam report their bionformatics-based investigation of highly conserved, intragenic promoter elements in 11 multicellular, eukaryotic genomes. "We identified a highly conserved TATA motif followed by a CAA-motif in the tRNA upstream regions of all plant genomes," the authors report, adding that "strikingly, the 5'-flanking tRNA regions of the animal genomes are highly heterogeneous and lack a common conserved sequence signature." Based on subsequent deep-sequencing analysis of 16 human tissues, the team suggests that the "anticodon-dependent 5'-flanking motifs provide a possible mechanism for independent regulation of the tRNA transcription in various human tissues."
Moon-Soo Kim and his colleagues at the University of California, Davis, describe "a zinc finger protein array for the visual detection of specific DNA sequences for diagnostic applications." These ZFP arrays, Kim et al. show, are "simple devices to identify bacterial double-stranded DNA sequences" in quantitative assays in fewer than five minutes. "ZFP arrays have the potential to be developed into a simple and rapid point-of-care diagnostic for the multiplexed detection of pathogens," the UC Davis team writes.
Investigators in China this week show that the miR-124 "exerts a different role in cell proliferation at the optic vesicle stage, the stage which precedes optic cup formation" in Xenopus. This neural-specific miRNA "negatively regulates expression of the proneural marker NeuroD1, a bHLH transcription factor for neuronal differentiation," the authors write, adding that the interaction between these elements had not been reported previously.