Close linkage of the mouse and human CD3 gamma- and delta-chain genes suggests that their transcription is controlled by common regulatory elements.
Antigen receptors on the T-cell surface are noncovalently associated with at least four invariant polypeptide chains, CD3-gamma, -delta, -epsilon, and -zeta. The mouse CD3-gamma gene, consisting of seven exons, was found to be highly homologous to the CD3-delta gene described earlier. Both the high level of sequence homology and the exon/intron organization indicate that the CD3-gamma and -delta genes arose by gene duplication. Surprisingly, murine and human genomic DNA clones could be isolated that contained elements of both the CD3-gamma and CD3-delta genes. In fact, the putative transcription start site of the mouse CD3-gamma gene is less than 1.4 kilobases from the transcription initiation site of the mouse CD3-delta gene. Common elements that regulate the divergent transcription of the two genes are therefore proposed to be located in the intervening 1.4-kilobase DNA segment. This might contribute to the coordinate expression of the CD3-gamma and -delta genes during intrathymic maturation of T lymphocytes.
Saito
H
H
Division of Tumor Immunology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115.
Koyama
T
T
Georgopoulos
K
K
Clevers
H
H
Haser
W G
WG
LeBien
T
T
Tonegawa
S
S
Terhorst
C
C
D000595:Amino Acid Sequence; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics*; D001483:Base Sequence; D017252:CD3 Complex; D004262:DNA Restriction Enzymes; D005091:Exons; D005786:Gene Expression Regulation; D008040:Genetic Linkage; D006801:Humans; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D014158:Transcription, Genetic
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D004262:DNA Restriction Enzymes