Tandem linkage and unusual RNA splicing of the T-cell receptor beta-chain variable-region genes.
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.
Chou
H S
HS
Anderson
S J
SJ
Louie
M C
MC
Godambe
S A
SA
Pozzi
M R
MR
Behlke
M A
MA
Huppi
K
K
Loh
D Y
DY
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D005796:Genes; D008040:Genetic Linkage; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D046911:Macromolecular Substances; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D014158:Transcription, Genetic
D007135:Immunoglobulin Variable Region; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D004247:DNA