CD3-ZETA AND ETA-CHAINS ARE PRODUCED BY ALTERNATIVE SPLICING FROM A COMMON GENE

We have analyzed the genomlc organization of the murlne CD3η gene. As suggested from the sequence of CD3η cDNA, exons I-VII are identical to those of CD3ζ and exon VIII Is a unique exon for CD3η. Exon VIII of the CD3η gene is located 4 kb downstream of exon VIII of the CD3ζ gene. Together with the existence of a splicing acceptor site Just before exon VIII of the CD3η gene, the CD3η chain Is proved to be produced by an alternatively spliced transcript of the common gene of CD3ζ and η. Since T cell receptor complex contains two forms of ζ dimers, ζ-ζ and ζ- η, on a single T cell, which seem to have different functions, the results Indicate the importance of analyzing the regulation of the alternative splicing to understand T cell function. © 1990 Oxford University Press.