Toggle Main Menu Toggle Search

Open Access padlockePrints

Disparate roles of ATR and ATM in immunoglobulin class switch recombination and somatic hypermutation

Lookup NU author(s): Dr Victor Ruiz-Perez, Professor Judith Goodship



Class switch recombination (CSR) and somatic hypermutation (SHM) are mechanistically related processes initiated by activation-induced cytidine deaminase. Here, we have studied the role of ataxia telangiectasia and Rad3-related protein (ATR) in CSR by analyzing the recombinational junctions, resulting from in vivo switching, in cells from patients with mutations in the ATR gene. The proportion of cells that have switched to immunoglobulin (Ig)A and IgG in the peripheral blood seems to be normal in ATR-deficient (ATRD) patients and the recombined S regions show a normal "blunt end-joining," but impaired end joining with partially complementary (1-3 bp) DNA ends. There was also an increased usage of microhomology at the μ-α switch junctions, but only up to 9 bp, suggesting that the endjoining pathway requiring longer microhomologies (>10 bp) may be ATR dependent. The SHM pattern in the Ig variable heavy chain genes is altered, with fewer mutations occurring at A and more mutations at T residues and thus a loss of strand bias in targeting A/T pairs within certain hotspots. These data suggest that the role of ATR is partially overlapping with that of ataxia telangiectasia-mutated protein, but that the former is also endowed with unique functional properties in the repair processes during CSR and SHM. JEM © The Rockefeller University Press.

Publication metadata

Author(s): Pan-Hammarstrom Q, Lahdesmaki A, Zhao Y, Du L, Zhao Z, Wen S, Ruiz-Perez VL, Dunn-Walters DK, Goodship JA, Hammarstrom L

Publication type: Article

Publication status: Published

Journal: Journal of Experimental Medicine

Year: 2006

Volume: 203

Issue: 1

Pages: 99-110

ISSN (print): 0022-1007

ISSN (electronic): 1540-9538

Publisher: Rockefeller University Press


DOI: 10.1084/jem.20050595

PubMed id: 16390936


Altmetrics provided by Altmetric


Funder referenceFunder name
G0000160Medical Research Council