Characterization of a new subgroup of human Ig V lambda cDNA clone and its expression.
From a human bone marrow cDNA library, we have cloned and sequenced a gene which cross-hybridized with murine pre-B cell-specific gene 8HS-20 cDNA under the low-stringent condition. Sequence analysis predicted that this gene (YM-1) encoded 240 amino acids which had the basic structure of immunoglobulin lambda light chain. The 3' half of the YM-1 sequence was identical to the J lambda 2 C lambda 2 region except for four nucleotides. The 5' part of the gene had 87.6% sequence homology with the reported V lambda gene called T1. Comparison of the deduced amino acid sequences with representative members of the seven other V lambda subgroups showed considerable structural homology, but the maximum homology with these chains was 44%. Therefore, we conclude that YM-1 belongs to a new V lambda subgroup. Interestingly YM-1 showed higher homology with VpreB1 (56%) than with any of the other V lambda subgroups. By Southern blot analysis four to six cross-hybridizing V lambda bands were detected at high stringency. Expression of the V lambda gene was observed in immature as well as mature B cell lines without accompanying V-JC gene joining, suggesting that V lambda of the YM-1 locus is activated at the early stage of maturation.
Tsunetsugu-Yokota
Y
Y
Department of Cellular Immunology, National Institute of Health, Tokyo, Japan.
Minekawa
T
T
Shigemoto
K
K
Shirasawa
T
T
Takemori
T
T
D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000502:physiology; D001483:Base Sequence; D015139:Blotting, Southern; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D005803:Genes, Immunoglobulin; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment
D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains; D012333:RNA, Messenger; D004247:DNA