Immunoglobulin iota chain (VPREB1)

Immunoglobulin iota chain (VPREB1) is a 126-amino acid protein (16-18 kDa), encoded by the VPREB1 gene on chromosome 22. It is expressed selectively during the early stages of B cell development (pro-B and early pre-B cells), where it forms a non-covalent complex with CD179b (lambda5), known as the surrogate (or pseudo) light chain. Together, VPREB1 and CD179b associate with the Ig mu heavy chain and signal transducers (CD79a/CD79b) to produce the pre-B cell receptor (preBCR), essential for B lymphocyte maturation. This receptor complex regulates immunoglobulin gene rearrangement, allelic exclusion at the Ig heavy chain locus, and promotes Ig light chain gene rearrangements, acting as a functional checkpoint in B cell development. No human diseases are directly linked exclusively to VPREB1 mutations or dysfunction, but deficiencies in associated components result in severe impairment of B cell development, leading to immunodeficiencies such as agammaglobulinemia. VPREB1 is considered a diagnostic marker in some forms of leukemia and immune disorders, though it is not currently a direct therapeutic drug target[1][3][4][5][8].

Other names

V-set pre-B cell surrogate light chain 1VPREBCD179aImmunoglobulin iota chainCD179 antigen-like family member AProtein VPreB1pre-B lymphocyte 1IGIIGVPBCD179A