Immunoglobulin heavy chain isotype switch recombination is a regulated, irreversible, essential process of DNA deletion which alters genomic structure at the immunoglobulin heavy chain locus, joining a rearranged and expressed variable region to a new downstream constant region, deleting the DNA between. The result of switch recombination is to alter how an immunoglobulin molecule removes antigen without altering its specificity for antigen. Switch recombination is initiated by DNA deamination by the B cell-specific factor, AID, and in subsequent steps ubiquitous factors from distinct repair pathways collaborate to cleave and rejoin chromosomal DNA at the heavy chain locus. We propose to define how AID recognizes its DNA target (Aim 1);to determine the mechanisms of the redundant pathways of DNA cleavage, one dependent on uracile nucleoside glycosylase (UNG;
Aim 2), and on dependent on MSH2 (Aim 3);to define the sources of sequence heterogeneity and microhomology at switch junctions (Aim 4);and to study dynamic interactions of repair and recombination factors with transcriptionally activated switch regions in vivo (Aim 5). The results of these experiments will provide new understanding of a critical recombination process, and inform our understanding of how ubiquitous repair factors contribute to the immune response and maintain genomic stability.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM039799-22
Application #
7586237
Study Section
Molecular Genetics C Study Section (MGC)
Program Officer
Portnoy, Matthew
Project Start
1988-04-01
Project End
2011-03-31
Budget Start
2009-04-01
Budget End
2011-03-31
Support Year
22
Fiscal Year
2009
Total Cost
$325,673
Indirect Cost
Name
University of Washington
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Yabuki, Munehisa; Cummings, W Jason; Leppard, John B et al. (2012) Antibody discovery ex vivo accelerated by the LacO/LacI regulatory network. PLoS One 7:e36032
Yabuki, Munehisa; Ordinario, Ellen C; Cummings, W Jason et al. (2009) E2A acts in cis in G1 phase of cell cycle to promote Ig gene diversification. J Immunol 182:408-15
Ordinario, Ellen C; Yabuki, Munehisa; Larson, Ryan P et al. (2009) Temporal regulation of Ig gene diversification revealed by single-cell imaging. J Immunol 183:4545-53
Vallur, Aarthy C; Maizels, Nancy (2008) Activities of human exonuclease 1 that promote cleavage of transcribed immunoglobulin switch regions. Proc Natl Acad Sci U S A 105:16508-12
Vallur, A C; Yabuki, M; Larson, E D et al. (2007) AID in antibody perfection. Cell Mol Life Sci 64:555-65
Maizels, Nancy (2006) Dynamic roles for G4 DNA in the biology of eukaryotic cells. Nat Struct Mol Biol 13:1055-9
Maizels, Nancy (2005) Immunoglobulin gene diversification. Annu Rev Genet 39:23-46
Larson, Erik D; Duquette, Michelle L; Cummings, W Jason et al. (2005) MutSalpha binds to and promotes synapsis of transcriptionally activated immunoglobulin switch regions. Curr Biol 15:470-4
Larson, Erik D; Cummings, W Jason; Bednarski, David W et al. (2005) MRE11/RAD50 cleaves DNA in the AID/UNG-dependent pathway of immunoglobulin gene diversification. Mol Cell 20:367-75
Yabuki, Munehisa; Fujii, Monica M; Maizels, Nancy (2005) The MRE11-RAD50-NBS1 complex accelerates somatic hypermutation and gene conversion of immunoglobulin variable regions. Nat Immunol 6:730-6

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