Immunoglobulin (Ig) heavy chain class switch recombination occurs mainly by joining two switch (S) regions, segments of tandemly repeated DNA sequences that lie upstream of heavy chain constant region genes. The products of this recombination event are a chromosomal DNA joint and a 'looped-out' circular DNA joint. Although a previous study showed that 40% of chromosomal joints in the mu gene sw...

The immune system protects us from foreign substances or pathogens by generating specific antibodies. The variety of immunoglobulin (Ig) paratopes for antigen recognition is a result of the V(D)J rearrangement mechanism, while a fast and efficient immune response is mediated by specific immunoglobulin isotypes obtained through class switch recombination (CSR). To get a better understanding on h...

Wolf-Hirschhorn syndrome (WHS) is a genetic disease with characteristic facial features and developmental disorders. Of interest, loss of the MMSET gene (also known as WHSC1) is considered to be responsible for the core phenotypes of this disease. Patients with WHS also display Ab deficiency, although the underlying cause of this deficiency is unclear. Recent studies suggest that the histone me...

DNA double-strand breaks (DSBs) serve as obligatory intermediates for Ig heavy chain (Igh) class switch recombination (CSR). The mechanisms by which DSBs are resolved to promote long-range DNA end-joining while suppressing genomic instability inherently associated with DSBs are yet to be fully elucidated. Here, we use a targeted short-hairpin RNA screen in a B-cell lymphoma line to identify the...