The DNA-binding protein CTCF limits proximal Vκ recombination and restricts κ enhancer interactions to the immunoglobulin κ light chain locus.
Regulation of immunoglobulin (Ig) V(D)J gene rearrangement is dependent on higher-order chromatin organization. Here, we studied the in vivo function of the DNA-binding zinc-finger protein CTCF, which regulates interactions between enhancers and promoters. By conditional deletion of the Ctcf gene in the B cell lineage, we demonstrate that loss of CTCF allowed Ig heavy chain recombination, but pre-B cell proliferation and differentiation was severely impaired. In the absence of CTCF, the Igκ light chain locus showed increased proximal and reduced distal Vκ usage. This was associated with enhanced proximal Vκ and reduced Jκ germline transcription. Chromosome conformation capture experiments demonstrated that CTCF limits interactions of the Igκ enhancers with the proximal V(κ) gene region and prevents inappropriate interactions between these strong enhancers and elements outside the Igκ locus. Thus, although Ig gene recombination can occur in the absence of CTCF, it is a critical factor determining Vκ segment choice for recombination.
Department of Pulmonary Medicine, Erasmus MC Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
Claudia
C
Ribeiro de Almeida
Ralph
R
Stadhouders
Marjolein J W
MJ
de Bruijn
Ingrid M
IM
Bergen
Supat
S
Thongjuea
Boris
B
Lenhard
Wilfred
W
van Ijcken
Frank
F
Grosveld
Niels
N
Galjart
Eric
E
Soler
Rudi W
RW
Hendriks
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D000076246:CCCTC-Binding Factor; D002454:Cell Differentiation; D049109:Cell Proliferation; D056426:Genetic Loci; D007145:Immunoglobulin kappa-Chains / Q000235:genetics* / Q000276:immunology; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D011995:Recombination, Genetic; D012097:Repressor Proteins / Q000235:genetics* / Q000276:immunology; D014158:Transcription, Genetic
D000076246:CCCTC-Binding Factor; C000619698:Ctcf protein, mouse; D007145:Immunoglobulin kappa-Chains; D011947:Receptors, Antigen, B-Cell; D012097:Repressor Proteins