Cutting Edge: Proper Orientation of CTCF Sites in Cer Is Required for Normal J?-Distal and J?-Proximal V? Gene Usage.

ABSTRACT: Ig? locus contraction and V? gene usage are controlled by Cer, a cis-acting sequence in the V?-J? intervening region. This effect is attributed to two CTCF-binding sites within Cer that are oriented toward the V? gene region. However, the importance of Cer CTCF orientation in regulating V?J? rearrangement is unknown. We used CRISPR/Cas9 editing to delete and invert Cer in murine Abl pro-B cell lines. This revealed that Cer orientation is critical because clones with either an inverted or deleted Cer element show skewing toward J?-proximal V? gene usage. However, only Cer deletion increased J?-proximal V? germline transcription, suggesting an insulating function of Cer. Lastly, circularized chromosome conformation capture interaction data show that Cer CTCF orientation regulates long-range interactions with inversion clones displaying fewer interactions with regions in the middle and distal parts of the V? locus and more interactions to downstream regions compared with wild-type or deletion clones.

SUBMITTER: Kleiman E 

PROVIDER: S-EPMC6125182 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature