Identification of genes for the constant region of rabbit T-cell receptor beta chains.
We describe cDNA clones from thymus mRNA of a young rabbit that have sequences highly homologous to the human and murine T-cell receptor beta-chain constant region (C beta). In rabbit, man, and mouse there is a conserved extra cysteine in the constant region that could lead to a free thiol group or alternative disulfide bond formation depending on the locations and total numbers of cysteines in assembled receptor molecules. A cDNA clone (CL ANA 11) with 571 bases 5' of the C beta coding sequence has an open reading frame starting at a methionine codon that encodes 141 amino acids in frame with the C beta sequence. The encoded sequence has no resemblance to known immunoglobulin or beta-chain variable regions or other known proteins. An oligonucleotide probe from the 5' end of the encoded protein hybridizes to an approximately equal to 2-kilobase genomic DNA fragment that contains C beta gene sequences and to an approximately equal to 8-kilobase mRNA species in the thymus mRNA preparation from which the clone was derived. Within the 5' coding sequence there is a stretch of 211 bases containing strings of alternating purines and pyrimidines that may form Z-DNA. The sequence of the last 55 base pairs adjacent to C beta resembles the corresponding segment of mouse cDNA clone 86T3 that contains sequence 5' of the mouse C beta 1 gene. Although the function of a potential protein encoded by the 5' end of CL ANA 11 is unknown, it could play a role in regulation of thymocyte growth and differentiation.
Angiolillo
A L
AL
Lamoyi
E
E
Bernstein
K E
KE
Mage
R G
RG
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000032:analysis; D004262:DNA Restriction Enzymes / Q000378:metabolism; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000235:genetics*; D007136:Immunoglobulins / Q000235:genetics*; D046911:Macromolecular Substances; D051379:Mice; D010957:Plasmids; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013950:Thymus Gland / Q000032:analysis
D007127:Immunoglobulin Constant Regions; D007136:Immunoglobulins; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D004247:DNA; D004262:DNA Restriction Enzymes