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Induction and Assessment of Class Switch Recombination in Purified Murine B Cells
09:49

Induction and Assessment of Class Switch Recombination in Purified Murine B Cells

Published on: August 13, 2010

An evolutionarily conserved target motif for immunoglobulin class-switch recombination

Ali A Zarrin1, Frederick W Alt, Jayanta Chaudhuri

  • 1Howard Hughes Medical Institute, The Children's Hospital, CBR Institute for Biomedical Research, and Department of Genetics, Harvard University Medical School, Boston, Massachusetts 02115, USA.

Nature Immunology
|November 9, 2004
PubMed

Immunoglobulin H class-switch recombination (CSR) occurs between switch regions and requires transcription and activation-induced cytidine deaminase (AID). Transcription through mammalian switch regions, because of their GC-rich composition, generates stable R-loops, which provide single-stranded DNA substrates for AID. However, we show here that the Xenopus laevis switch region S(mu), which is rich in AT and not prone to form R-loops, can functionally replace a mouse switch region to mediate CSR in vivo. X. laevis S(mu)-mediated CSR occurred mostly in a region of AGCT repeats targeted by the AID-replication protein A complex when transcribed in vitro. We propose that AGCT is a primordial CSR motif that targets AID through a non-R-loop mechanism involving an AID-replication protein A complex.

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