Activation-induced cytidine deaminase targets DNA at sites of RNA polymerase II stalling by interaction with Spt5.
Activation-induced cytidine deaminase (AID) initiates antibody gene diversification by creating U:G mismatches. However, AID is not specific for antibody genes; Off-target lesions can activate oncogenes or cause chromosome translocations. Despite its importance in these transactions little is known about how AID finds its targets. We performed an shRNA screen to identify factors required for class switch recombination (CSR) of antibody loci. We found that Spt5, a factor associated with stalled RNA polymerase II (Pol II) and single stranded DNA (ssDNA), is required for CSR. Spt5 interacts with AID, it facilitates association between AID and Pol II, and AID recruitment to its Ig and non-Ig targets. ChIP-seq experiments reveal that Spt5 colocalizes with AID and stalled Pol II. Further, Spt5 accumulation at sites of Pol II stalling is predictive of AID-induced mutation. We propose that AID is targeted to sites of Pol II stalling in part via its association with Spt5.
Pavri
Rushad
R
Laboratory of Molecular Immunology, The Rockefeller University, New York, New York 10065, USA.
Gazumyan
Anna
A
Jankovic
Mila
M
Di Virgilio
Michela
M
Klein
Isaac
I
Ansarah-Sobrinho
Camilo
C
Resch
Wolfgang
W
Yamane
Arito
A
Reina San-Martin
Bernardo
B
Barreto
Vasco
V
Nieland
Thomas J
TJ
Root
David E
DE
Casellas
Rafael
R
Nussenzweig
Michel C
MC
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D003564:Cytidine Deaminase / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D017578:Immunoglobulin Class Switching; D007136:Immunoglobulins / Q000235:genetics; D051379:Mice; D012319:RNA Polymerase II / Q000378:metabolism*; D035602:Transcriptional Elongation Factors / Q000378:metabolism*; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
D002868:Chromosomal Proteins, Non-Histone; D007136:Immunoglobulins; D035602:Transcriptional Elongation Factors; C069940:SPT5 transcriptional elongation factor; D012319:RNA Polymerase II; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase