Project description:The dynamic folding of genomes regulates numerous biological processes, including antigen receptor (AgR) gene assembly. We show that, unlike other AgR loci, homotypic chromatin interactions and bi-directional chromosome looping both contribute to structuring Tcrb for efficient long-range V(D)J recombination. Inactivation of the CTCF binding element (CBE) or promoter at the most 5’Vβ segment (Trbv1) impaired loop extrusion originating locally and extending to DβJβ CBEs at the opposite end of Tcrb. Promoter or CBE mutation nearly eliminated Trbv1 contacts and decreased RAG endonuclease-mediated Trbv1 recombination. Importantly, Trbv1 rearrangement can proceed independent of substrate orientation, ruling out scanning by DβJβ-bound RAG as the sole mechanism of Vβ recombination, distinguishing it from Igh. Our data indicate that CBE-dependent generation of loops cooperates with promoter-mediated activation of chromatin to juxtapose Vβ and DβJβ segments for recombination through diffusion-based synapsis. Thus, the mechanisms that fold a genomic region can influence molecular processes occurring in that space, which may include recombination, repair, and transcriptional programming.

2024-01-04 | GSE249647 | GEO

Locus folding mechanisms determine modes of antigen receptor gene assembly (Hi-C)

2024-01-04 | GSE249646 | GEO

Locus folding mechanisms determine modes of antigen receptor gene assembly (RNA-seq)

2024-01-04 | GSE249648 | GEO

Locus folding mechanisms determine modes of antigen receptor gene assembly

Project description:This SuperSeries is composed of the SubSeries listed below.

2024-01-04 | GSE249649 | GEO

Application of long read sequencing to determine expressed antigen diversity in Trypanosoma brucei infections.

Project description:Application of long read sequencing to determine expressed antigen diversity in Trypanosoma brucei infections.

| PRJNA472801 | ENA

High-throughput RNA structure probing reveals critical folding events during early 60S ribosome assembly in yeast.

Project description:While the protein composition of various yeast 60S ribosomal subunit assembly intermediates has been studied in detail, little is known about ribosomal RNA (rRNA) structural rearrangements that take place during early 60S assembly steps. Using a high-throughput RNA structure probing method, we provide nucleotide resolution insights into rRNA structural rearrangements during nucleolar 60S assembly. Our results suggest that many rRNA-folding steps, such as folding of 5.8S rRNA, occur at a very specific stage of assembly, and propose that downstream nuclear assembly events can only continue once 5.8S folding has been completed. Our maps of nucleotide flexibility enable making predictions about the establishment of protein-rRNA interactions, providing intriguing insights into the temporal order of protein-rRNA as well as long-range inter-domain rRNA interactions. These data argue that many distant domains in the rRNA can assemble simultaneously during early 60S assembly and underscore the enormous complexity of 60S synthesis.Ribosome biogenesis is a dynamic process that involves the ordered assembly of ribosomal proteins and numerous RNA structural rearrangements. Here the authors apply ChemModSeq, a high-throughput RNA structure probing method, to quantitatively measure changes in RNA flexibility during the nucleolar stages of 60S assembly in yeast.

2017-10-04 | GSE83821 | GEO

Asymmetrical forward and reverse developmental trajectories determine molecular programs of B cell antigen receptor editing

Project description:Asymmetrical forward and reverse developmental trajectories determine molecular programs of B cell antigen receptor editing

| PRJNA726541 | ENA