BCR Gene

The BCR gene (BCR is the acronym for breakpoint cluster region) is a human gene that is localized on the long arm of chromosome 22 (22q11.23) and has 23 exons. The physiological function of the BCR gene product is not yet known. The encoded protein has a serine/threonine kinase activity and is a GTPase-activating protein for the protein p21rac (renal carcinoma antigen NY-REN-26).

Two mRNA variants of the BCR gene have been found that code for different isoforms. Together with the ABL1 gene, the BCR gene is involved in the reciprocal translocation t(9;22)(q34;q11), which leads to the Philadelphia chromosome.

The NFE2 Like BZIP Transcription Factor 2 (see NFEL2 gene below), a transcription factor plays a key role in the response to oxidative stress. The transcription factor binds to antioxidant response elements (ARE), which are present in the promoter region of many cytoprotective genes, and promotes their expression (Sanghvi VR et al. 2019). Under normal conditions, this protein is ubiquitinated and degraded in the cytoplasm by the B-Cell Receptor Complex(BCR complex) (Huang HC et al. 2000). In response to oxidative stress, electrophilic metabolites inhibit the activity of the BCR(KEAP1) complex and promote nuclear accumulation of NFE2L2/NRF2, heterodimerization with one of the small Maf proteins and binding to ARE elements of cytoprotective target genes (Mills EL et al. 2018).

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