Tandem linkage and unusual RNA splicing of the T-cell receptor beta-chain variable-region genes.

AUTOR(ES)

Chou, H S

RESUMO

The variable-region (V) genes of the murine T-cell receptor beta chain exist largely as single-element subfamilies. The V beta 5 and V beta 8 genes belong to the only two known three-member V beta subfamilies. We present studies on the linkage of these six genes and show that the genomic organization is that of alternating V beta 5 and V beta 8 genes. Our analysis suggests that these genes were tandemly duplicated, the unit of duplication being a pair of V beta 5 and V beta 8 genes. This tandem organization permits transcripts to initiate from the promoter of an unrearranged V beta located upstream of the rearranged V beta gene. These transcripts can generate functional beta-chain gene messages by novel RNA splicing of the upstream leader exon to the V beta coding exon of the downstream rearranged gene. We extend the analysis of the T-cell receptor genomic organization to include 12 V beta genes and suggest that all V beta genes are closely linked on chromosome 6. In addition, we discuss the possible implications of the close linkage of the V beta genes on the development of the T-cell receptor beta-chain gene repertoire.

Documentos Relacionados

• Diversity and structure of human T-cell receptor beta-chain variable region genes.
• Murine T-cell receptor mutants with deletions of beta-chain variable region genes.
• Multiple nuclear proteins bind upstream sequences in the promotor region of a T-cell receptor beta-chain variable-region gene: evidence for tissue specificity.
• Sequence and evolution of the human T-cell antigen receptor beta-chain genes.
• Rearrangement of T-cell receptor beta-chain genes during T-cell development.