Immunoglobulin lambda locus, also known as IGL@, is a region on human chromosome 22 that contains genes for the lambda light chains of antibodies (or immunoglobulins).[2]
Immunoglobulins recognize foreign antigens and initiate immune responses such as phagocytosis and the complement system. Each immunoglobulin molecule consists of two identical heavy chains and two identical light chains. There are two classes of light chains, kappa and lambda. This region represents the germline organization of the lambda light chain locus. The locus includes V (variable), J (joining), and C (constant) segments. During B cell development, a recombination event at the DNA level joins a single V segment with a J segment; the C segment is later joined by splicing at the RNA level. Recombination of many different V segments with several J segments provides a wide range of antigen recognition. Additional diversity is attained by junctional diversity, resulting from the random additional of nucleotides by terminal deoxynucleotidyltransferase, and by somatic hypermutation, which occurs during B cell maturation in the spleen and lymph nodes. Several V segments and three C segments are known to be incapable of encoding a protein and are considered pseudogenes. The locus also includes several non-immunoglobulin genes, many of which are pseudogenes or are predicted by automated computational analysis or homology to other species.[2]
Genes[]
The immunoglobulin lambda locus contains the following genes:
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Hieter PA, Korsmeyer SJ, Waldmann TA, Leder P (1981). "Human immunoglobulin kappa light-chain genes are deleted or rearranged in lambda-producing B cells". Nature. 290 (5805): 368–72. Bibcode:1981Natur.290..368H. doi:10.1038/290368a0. PMID6783958. S2CID4333721.
Erikson J, Martinis J, Croce CM (1982). "Assignment of the genes for human lambda immunoglobulin chains to chromosome 22". Nature. 294 (5837): 173–5. doi:10.1038/294173a0. PMID6795508. S2CID22056008.
Frippiat JP, Williams SC, Tomlinson IM, et al. (1995). "Organization of the human immunoglobulin lambda light-chain locus on chromosome 22q11.2". Hum. Mol. Genet. 4 (6): 983–91. doi:10.1093/hmg/4.6.983. PMID7655473.
Williams SC, Frippiat JP, Tomlinson IM, et al. (1997). "Sequence and evolution of the human germline V lambda repertoire". J. Mol. Biol. 264 (2): 220–32. doi:10.1006/jmbi.1996.0636. PMID8951372.
Boursier L, Su W, Spencer J (2003). "Imprint of somatic hypermutation differs in human immunoglobulin heavy and lambda chain variable gene segments". Mol. Immunol. 39 (16): 1025–34. doi:10.1016/S0161-5890(03)00033-6. PMID12749909.