Fundamental roles of chromatin loop extrusion in antibody class switching.

ABSTRACT: Antibody class switch recombination (CSR) in B lymphocytes replaces immunoglobulin heavy chain locus (Igh) Cμ constant region exons (C_Hs) with one of six C_Hs lying 100-200 kb downstream¹. Each C_H is flanked upstream by an I promoter and long repetitive switch (S) region¹. Cytokines and activators induce activation-induced cytidine deaminase (AID)² and I-promoter transcription, with 3' IgH regulatory region (3' IgHRR) enhancers controlling the latter via I-promoter competition for long-range 3' IgHRR interactions^3-8. Transcription through donor Sμ and an activated downstream acceptor S-region targets AID-generated deamination lesions at, potentially, any of hundreds of individual S-region deamination motifs^9-1

SUBMITTER: Zhang X 

PROVIDER: S-EPMC6856444 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature