title: Activation-induced deoxycytidine deaminase (AID) co-transcriptional scanning at single-molecule resolution.
abstract: Activation-induced deoxycytidine deaminase (AID) generates antibody diversity in B cells by initiating somatic hypermutation (SHM) and class-switch recombination (CSR) during transcription of immunoglobulin variable (IgV) and switch region (IgS) DNA. Using single-molecule FRET, we show that AID binds to transcribed dsDNA and translocates unidirectionally in concert with RNA polymerase (RNAP) on moving transcription bubbles, while increasing the fraction of stalled bubbles. AID scans randomly when constrained in an 8 nt model bubble. When unconstrained on single-stranded (ss) DNA, AID moves in random bidirectional short slides/hops over the entire molecule while remaining bound for ∼ 5 min. Our analysis distinguishes dynamic scanning from static ssDNA creasing. That AID alone can track along with RNAP during transcription and scan within stalled transcription bubbles suggests a mechanism by which AID can initiate SHM and CSR when properly regulated, yet when unregulated can access non-Ig genes and cause cancer.
authors.affiliation: Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, USA.
authors.forename: Gayan
authors.initials: G
authors.lastname: Senavirathne
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Bertram
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Jaszczur
authors.affiliation: Department of Medicine, Section of Virology, Imperial College London, Du Cane Road, London W12 0NN, UK.|Single Molecule Imaging Group, MRC Clinical Sciences Center, Imperial College London, Du Cane Road, London W12 0NN, UK.
authors.forename: Kathy R
authors.initials: KR
authors.lastname: Chaurasiya
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Phuong
authors.initials: P
authors.lastname: Pham
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA.|Center for Applied Mathematical Science, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Chi H
authors.initials: CH
authors.lastname: Mak
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA.|Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Myron F
authors.initials: MF
authors.lastname: Goodman
authors.affiliation: Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, USA.|Department of Medicine, Section of Virology, Imperial College London, Du Cane Road, London W12 0NN, UK.|Single Molecule Imaging Group, MRC Clinical Sciences Center, Imperial College London, Du Cane Road, London W12 0NN, UK.
authors.forename: David
authors.identifier: http://orcid.org/0000-0003-4657-6323
authors.initials: D
authors.lastname: Rueda
mesh_terms: D000818:Animals; D000916:Antibody Diversity / Q000235:genetics* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D003564:Cytidine Deaminase / Q000276:immunology / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli; D031541:Fluorescence Resonance Energy Transfer; D017578:Immunoglobulin Class Switching / Q000235:genetics / Q000276:immunology; D061987:Sf9 Cells; D027041:Somatic Hypermutation, Immunoglobulin / Q000235:genetics / Q000276:immunology; D018411:Spodoptera; D014158:Transcription, Genetic / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000378:metabolism*; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
chemical_list: D004277:DNA, Single-Stranded; D014764:Viral Proteins; D004247:DNA; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase