Dynamic modulation of enhancer-promoter and promoter-promoter connectivity in gene regulation.

Enhancers are short segments of regulatory DNA that control when and in which cell-type genes should be turned on in response to a variety of extrinsic and intrinsic signals. At the molecular level, enhancers serve as a genomic scaffold that recruits sequence-specific transcription factors and co-activators to facilitate transcription from linked promoters. However, it remains largely unclear how enhancers communicate with appropriate target promoters in the context of higher-order genome topology.

Dynamic interplay between non-coding enhancer transcription and gene activity in development.

Non-coding transcription at the intergenic regulatory regions is a prevalent feature of metazoan genomes, but its biological function remains uncertain. Here, we devise a live-imaging system that permits simultaneous visualization of gene activity along with intergenic non-coding transcription at single-cell resolution in Drosophila. Quantitative image analysis reveals that elongation of RNA polymerase II across the internal core region of enhancers leads to suppression of transcriptional bursting from linked genes.

A method for the isolation and characterization of autophagic bodies from yeast provides a key tool to investigate cargos of autophagy.

Autophagy is a major cellular degradation pathway that is highly conserved among eukaryotes. The identification of cargos captured by autophagosomes is critical to our understanding of the physiological significance of autophagy in cells, but these studies can be challenging because autophagosomes disintegrate easily. In the yeast Saccharomyces cerevisiae, cells deficient in the vacuolar lipase Atg15 accumulate autophagic bodies (ABs) within the vacuole following the induction of autophagy.

Selectivity of mRNA degradation by autophagy in yeast.

Synthesis and degradation of cellular constituents must be balanced to maintain cellular homeostasis, especially during adaptation to environmental stress. The role of autophagy in the degradation of proteins and organelles is well-characterized. However, autophagy-mediated RNA degradation in response to stress and the potential preference of specific RNAs to undergo autophagy-mediated degradation have not been examined.

The tRNA Splicing Endonuclease Complex Cleaves the Mitochondria-localized CBP1 mRNA.

The tRNA splicing endonuclease (Sen) complex is located on the mitochondrial outer membrane and splices precursor tRNAs in Saccharomyces cerevisiae. Here, we demonstrate that the Sen complex cleaves the mitochondria-localized mRNA encoding Cbp1 (cytochrome b mRNA processing 1). Endonucleolytic cleavage of this mRNA required two cis-elements: the mitochondrial targeting signal and the stem-loop 652-726-nt region.

Roles of mRNA fate modulators Dhh1 and Pat1 in TNRC6-dependent gene silencing recapitulated in yeast.

The CCR4-NOT complex, the major deadenylase in eukaryotes, plays crucial roles in gene expression at the levels of transcription, mRNA decay, and protein degradation. GW182/TNRC6 proteins, which are core components of the microRNA-induced silencing complex in animals, stimulate deadenylation and repress translation via recruitment of the CCR4-NOT complex. Here we report a heterologous experimental system that recapitulates the recruitment of CCR4-NOT complex by TNRC6 in S.

Dom34:hbs1 plays a general role in quality-control systems by dissociation of a stalled ribosome at the 3' end of aberrant mRNA.

Translation arrest leads to an endonucleolytic cleavage of mRNA that is termed no-go decay (NGD). It has been reported that the Dom34:Hbs1 complex stimulates this endonucleolytic cleavage of mRNA induced by translation arrest in vivo and dissociates subunits of a stalled ribosome in vitro. Here we report that Dom34:Hbs1 dissociates the subunits of a ribosome that is stalled at the 3' end of mRNA in vivo, and has a crucial role in both NGD and nonstop decay.

[A case of conversion disorder (hysteria) after spinal anesthesia].

We report a case of conversion disorder after spinal anesthesia. A 16-year-old healthy woman underwent arthroscopic surgery under spinal anesthesia. She showed tremor all over and it did not stop.