We have determined the DNA sequences in the J2-C2 intron of the T cell receptor (TCR) beta gene and analyzed nuclear proteins binding to this region. Previously, we identified two tissue-specific DNase I hypersensitive regions, potential regulatory regions, in the J-C intron. The DNA sequence of the J2-C2 intron revealed that both DNase I hypersensitive regions have similar DNA sequences, suggesting that these regions are evolutionarily conserved.
View Article and Find Full Text PDFDuring intrathymic differentiation, the genes coding for the T cell receptor/CD3 (TCR/CD3) complex are expressed in stages resulting in surface expression of competent receptors on the most mature T cells. The CD3-delta, gamma and epsilon proteins, which are expressed intracellularly in the earliest detectable cells of T lineage, form the core of the TCR/CD3 complex. In the present investigation aimed at understanding the tissue specific expression of the murine CD3-delta gene, a T cell specific DNase I hypersensitive site was found 0.
View Article and Find Full Text PDFThe murine T cell receptor V alpha 3 gene segment is associated with reactivity to p-azobenzenearsonate, as indicated by several independent lines of evidence. First, three out of four arsonate-reactive T cell clones tested (two I-Ad-and one I-Ak-restricted) utilized V alpha 3. Second, bulk splenic cultures enriched for arsonate/H-2d and arsonate/H-2k responsive T cells showed increased expression of V alpha 3 mRNA.
View Article and Find Full Text PDFThe developmental patterns of rearrangement and expression of the T-cell antigen-receptor genes are precisely regulated during T-cell differentiation and education. The beta- and gamma-subunit RNAs of the T-cell receptor are abundantly expressed in immature thymocytes. In mature thymocytes the alpha- and beta-subunit RNAs are preferentially expressed, whereas there is minimal expression of the gamma RNA.
View Article and Find Full Text PDFWe elaborate basic chemical principles and current laboratory procedures for sequencing end-labeled DNA by partial cleavage and gel electrophoresis (A. M. Maxam and W.
View Article and Find Full Text PDFSubtractive complementary DNA cloning combined with partial protein sequencing has allowed identification of the genes encoding the alpha and beta subunits of T-cell receptors. The subtractive cDNA library prepared from the cytotoxic T lymphocyte (Tc) clone 2C has been found to contain a third type of clone encoding the gamma chain. The gamma gene shares several features with the alpha and beta genes: (1) assembly from gene segments resembling immunoglobulin V, J and C (respectively variable, joining and constant region) DNA segments; (2) rearrangement and expression in T cells and not in B cells; (3) sequences reminiscent of transmembrane and intracytoplasmic regions of integral membrane proteins; (4) a cysteine residue at the position expected for an interchain disulphide bond.
View Article and Find Full Text PDFThe T-cell receptor beta-chain gene has a nuclease hypersensitive site in several kinds of T cells, which does not appear in B cells expressing immunoglobulins. Conversely, the kappa immunoglobulin gene shows a known hypersensitive site at its enhancer element in B cells, as expected, but this site is absent in T cells. As is the case with immunoglobulin genes, the T-cell receptor site lies within the gene, in the intron separating joining and constant region segments.
View Article and Find Full Text PDFThe herpes simplex virus type 1 genome (160 kilobases) contains three origins of DNA synthesis: two copies of oriS located within the repeated sequences flanking the short unique arm (US), and one copy of oriL located within the long unique arm (UL). Precise localization and characterization of oriL have been severely hampered by the inability to clone sequences which contain it (coordinates 0.398 to 0.
View Article and Find Full Text PDFWith contemporary molecular cloning and DNA sequencing techniques, deriving the primary structure of higher cell genes is now routine. This publication reviews the chemical DNA sequencing method, and suggests strategies for sequencing recombinant DNA, whether arising naturally by chromosome rearrangement in vivo or created experimentally by gene splicing in vitro. One such strategy prepares end-labeled restriction fragments from an inserted or rearranged DNA region, for sequencing by the chemical method.
View Article and Find Full Text PDFCol E1 DNA has methylated cytosine in the sequence 5'-CC*(A/T)GG-3' and methylated adenine in the sequence 5'-GA*TC-3' at the positions indicated by asterisks(*). When the Maxam-Gilbert DNA sequencing method is applied to this DNA, the methylated cytosine (5-methylcytosine) is found to be less reactive to hydrazine than are cytosine and thymine, so that a band corresponding to that base does not appear in the pyrimidine cleavage patterns. The existence of the methylated cytosine can be confirmed by analyzing the complementary strand or unmethylated DNA.
View Article and Find Full Text PDFThe genome of the Moloney strain of murine leukemia virus (Mo-MuLV) has been analyzed by digestion with ribonuclease T1 and separation of the digestion products by two-dimensional gel electrophoresis. Thirty large oligonucleotides isolated from such a fingerprint have been characterized. One of these oligonucleotides (number 21) was found to be present in twice the molar yield of the rest.
View Article and Find Full Text PDFDirect DNA sequence analysis of Saccharomyces cerevisiae ribosomal DNA cloned in an Escherichia coli plasmid revealed part of the structural gene for 5.8S rRNA at one end of a 700-base-pair EcoRI fragment. Taken with the previously established EcoRI restriction map of the ribosomal repeat unit, this sequence establishes that the yeast 5.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 1978
We have determined the sequence of the DNA of a germ-line gene for the variable region of a mouse immunoglobulin light chain, the VlambdaII gene. The sequence confirms that the variable region gene lies on the DNA separated from the constant region. Hypervariable region codons appear in the germ-line sequence.
View Article and Find Full Text PDFThe positions of adenines, guanines, and pyrimidines can be determined by partial nuclease digestion of a terminally labeles RNA molecule. In urea, at elevated temperatures, RNase T1 generates a pattern reflecting cleavage at guanines while RNase U2 cleaves only at adenine. A limited alkaline hydrolysis provides a continuum of fragments derived from breaks at every phosphodiester bond.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 1977
When Rous sarcoma virus RNA is transcribed into DNA by the reverse transcriptase, a tRNA primer is elongated into DNA. The primer is near the 5' end of the virus genome; the first major DNA made is a "run-off" product extending 101 bases from the primer to the 5' end of the template. We have studied this DNA molecule to determine the sequence of the first 101 bases at the 5' end of the Rous sarcoma virus genome (Prague strain, subgroup C).
View Article and Find Full Text PDFDNA can be sequenced by a chemical procedure that breaks a terminally labeled DNA molecule partially at each repetition of a base. The lengths of the labeled fragments then identify the positions of that base. We describe reactions that cleave DNA preferentially at guanines, at adenines, at cytosines and thymines equally, and at cytosines alone.
View Article and Find Full Text PDFA 2000 base pair (bp) DNA fragment can be excised from sea urchin (S. purpuratus) histone gene repeat units with restriction endonuclease Eco R1. This DNA, which has been cloned in a bacterial plasmid, is known to encompass two of the five histone genes.
View Article and Find Full Text PDFFull-length, single-stranded rabbit globin cDNA, synthesized by AMV reverse transcriptase, apparently contains a small double-stranded sequence (hairpin) at the 3' terminus. This cDNA can serve as template-primer for E. coli DNA polymerase I, which synthesizes a strand complementary to the cDNA and covalently bound to it.
View Article and Find Full Text PDFThe lac repressor protects the lac operator against digestion with deoxyribonuclease. The protected fragment is double-stranded and about 27 base-pairs long. We determined the sequence of RNA transcription copies of this fragment and present a sequence for 24 base pairs.
View Article and Find Full Text PDF