Open Access

REVIEW

The role of protein phosphorylation in the regulation of class switch recombination

KANO TANABE¹, RYUTARO KAJIHARA^2,3,*

1 Department of Medical Technology, Faculty of Health Science, Kumamoto Health Science University, Kumamoto, 861-5598, Japan
2 Department of Biomedical Laboratory Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, 862-0976, Japan
3 Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA

* Address correspondence to: Ryutaro Kajihara,

BIOCELL 2020, 44(4), 545-558. https://doi.org/10.32604/biocell.2020.012740

Received 11 July 2020; Accepted 14 September 2020; Issue published 24 December 2020

Abstract

Antibody is an important part of adaptive immune system and is produced only by B cells. There are five main classes (IgM, IgD, IgG, IgA, IgE) and some subclasses in antibodies. IgM and IgD are produced by mature naïve B cells. On the other hand, IgG, IgA and IgE are produced by activated antigen-specific B cells via class switch recombination (CSR). CSR is the irreversible DNA rearrangement from upstream to downstream classes in immunoglobulin heavy chain genes. Co-stimulations of CD40 ligand (CD40L) and cytokines are required for induction of CSR by activating several transcription factors. These signal transduction pathways involve many protein phosphorylation. Phosphorylation or dephosphorylation of cellular protein is an important kind of post-translational protein modification in intracellular signal transduction. In the fact, more than one third of the intracellular proteins are said to be transiently phosphorylated in human. A protein kinase is an enzyme that catalyzes the addition of phosphate to substrate protein. Whereas, a protein phosphatase catalyzes the removal of phosphate from the substrate. This review focuses on the mechanism of CSR controlled by protein phosphorylation and dephosphorylation. We provide the role of protein kinase and phosphatase in the regulation of class switch recombination.

---

Keywords

---