Kudo A, Sakaguchi N, Melchers F
EMBO J. 1987 Jan;6(1):103-7. doi: 10.1002/j.1460-2075.1987.tb04725.x.
lambda 5 is an immunoglobulin lambda light chain-related gene which is selectively transcribed in murine pre-B lymphocytes to yield a 1.2 kb poly(A)+ mRNA. Comparison of the nucleotide sequence of a 1 kb cDNA clone with the sequence of a genomic clone isolated from 70Z/3 murine pre-B lymphoma cells shows lambda 5 is composed of three exons spanning a 3.75 kb DNA segment. Conserved splice signal sequences at all exon/intron boundaries and the presence of a long open reading frame indicate that a functional mRNA molecule can be made. Exon I contains a cap-site and a potential ATG start codon as well as sequences encoding a signal peptide. This gene could encode a lambda 5 protein of 209 amino acids which has, however, not yet been identified. The 3' portion of exon II and all of exon III shows strong sequence homologies to J lambda L and C lambda L exons. Homology to the lambda L chain genes is lost in the 5' portion of exon II and throughout exon I. In exon I short homologies to leader sequences and to VH framework 1 sequences are seen.
λ5是一个与免疫球蛋白λ轻链相关的基因，它在小鼠前B淋巴细胞中被选择性转录，产生一个1.2 kb的多聚腺苷酸化（poly(A)+）mRNA。将一个1 kb cDNA克隆的核苷酸序列与从70Z/3小鼠前B淋巴瘤细胞中分离出的基因组克隆的序列进行比较，结果显示λ5由三个外显子组成，跨越一个3.75 kb的DNA片段。所有外显子/内含子边界处保守的剪接信号序列以及一个长开放阅读框的存在表明，可以产生一个功能性的mRNA分子。外显子I包含一个帽位点、一个潜在的ATG起始密码子以及编码信号肽的序列。该基因可能编码一个由209个氨基酸组成的λ5蛋白，然而，该蛋白尚未被鉴定出来。外显子II的3'部分和整个外显子III与JλL和CλL外显子具有很强的序列同源性。在外显子II的5'部分和整个外显子I中，与λ轻链基因的同源性消失。在外显子I中，可以看到与前导序列和VH框架1序列的短同源性。
