CD3 zeta/eta/theta locus is colinear with and transcribed antisense to the gene encoding the transcription factor Oct-1.
CD3 zeta and eta are signal-transducing components of the TCR and are derived from alternative splicing of transcripts from a single genetic locus that also encodes CD30 theta. We have isolated two murine cDNA clones that appear to result from antisense transcription through CD3 theta-specific exon 10 and CD3 eta-specific exon 9. The sequence of these clones shows no open reading frame. Northern analysis with single stranded probes confirms the existence of a ubiquitously expressed > 12-kb polyadenylated mRNA antisense to CD3 eta. A "genomic walk," which extended 32 kb distal to murine CD3 eta exon 9, provided genomic DNA containing a more 5' portion of the antisense transcript. This probe identified two murine thymic cDNA with 91% sequence homology to the human transcription factor Oct-1. Five exons of murine Oct-1 map in an antisense orientation to the CD3 zeta/eta/theta locus on the cloned genomic sequences. The murine Oct-1 cDNA and exon 9 of CD3 eta hybridize to the same > 12-kb mRNA. Similarly, human Oct-1 and previously characterized human genomic sequences homologous to murine CD3 eta exon 9 each hybridize to the same > 15-kb human mRNA. Thus, the CD3 zeta/eta/theta and Oct-1 gene loci are partially overlapping and transcribed in opposite directions. The potential functional implications of these findings are discussed.
Laboratory of Immunobiology, Harvard Medical School, Boston, MA 02115.
A
A
Lerner
L
L
D'Adamio
A C
AC
Diener
L K
LK
Clayton
E L
EL
Reinherz
D000595:Amino Acid Sequence; D001483:Base Sequence; D017252:CD3 Complex / Q000235:genetics*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D004268:DNA-Binding Proteins / Q000235:genetics*; D005091:Exons; D005786:Gene Expression Regulation; D005796:Genes; D005807:Genes, Overlapping; D051863:Host Cell Factor C1; D006801:Humans; D008969:Molecular Sequence Data; D050811:Octamer Transcription Factor-1; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D017252:CD3 Complex; D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; D051863:Host Cell Factor C1; D050811:Octamer Transcription Factor-1; D009838:Oligodeoxyribonucleotides; C494165:POU2F1 protein, human; D012333:RNA, Messenger; D014157:Transcription Factors