Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transcription of the complete mouse mammary tumor virus (MMTV) proviral genome in mouse cells is controlled by a strong promoter in its long terminal repeat. In the mouse T lymphoma EL4, there is a second, activation-dependent transcriptional initiation site within the envelope (env) gene, from which a short mRNA is generated, encoding the open reading frame of the long terminal repeat. We now report the isolation of a segment of the MMTV env gene (called META, for MMTV env transcriptional activator) which has the expected transcription-activating properties seen in EL4.E1 cells. Namely, it induces activation-dependent, T-lymphocyte-specific transcription of a chloramphenicol acetyltransferase reporter gene. It is active in mouse or human T-helper lymphocyte lines when they are stimulated to transcribe lymphokine genes but is inactive in unstimulated T-helper cells, fibroblasts, a cytotoxic T-lymphocyte line, and a mastocytoma cell line. Its activity is inhibited by cyclosporin A, a specific inhibitor of lymphokine transcription. Several forms of the META have been isolated from EL4.E1 cells, a mouse T-helper cell hybridoma, and from BALB/c spleen cells. Linked to the heterologous thymidine kinase promoter, a 400-bp portion of it is an inducible, orientation-independent, and cyclosporin A-sensitive transcriptional activator in T-helper cells.
 ...
PMID:An activation-dependent, T-lymphocyte-specific transcriptional activator in the mouse mammary tumor virus env gene. 132 Jan 98

The chromosomal complements of somatic cell pig-mink hybrids was determined by a new approach. This approach includes microdissection of metaphase chromosomes, generation of chromosome and region-specific DNA libraries, and fluorescence in situ hybridization of these libraries with pig lymphocyte chromosomes. The studied hybrid cells were shown to contain two small acrocentric chromosomes and a microchromosome of porcine origin. Identification of these chromosomes by differential GTG-staining was impossible. Chromosome isolation by a micromanipulation technique followed by DNA amplification in TOPO-DOP polymerase chain reaction provided chromosome-specific DNA libraries of the rearranged chromosomes. Based on these libraries, the labeled DNA probes were prepared and hybridized to pig chromosomes. This allowed us to determine the origin of the material contributing to the hybrid cell chromosomes. One of these chromosomes contained five pig chromosomal regions: 15cen-q2; 6q21-q23; 13q21; 13q22; 7q25-qter, while the other contained the following pig chromosomal regions: 4p12-p13; 16q12-q14; 12pter-p15. The microchromosome contained the Xp11-Xq11 region. The minimal size of the revealed chromosomal regions was about 3 to 4 x 10(6) bp. Segregation analysis of the thymidine kinase gene 1 (TK1), which was earlier localized to the pig 12p region, and the hybrid cell pig chromosomes in the hybrid subclones suggested that TK1 gene can be assigned to 12p15-pter. The results obtained demonstrate the efficiency of the applied approach in its detailed and reliable description of complex chromosomal rearrangements in hybrid clones, when differential chromosome staining failed to identify these chromosomes.
 ...
PMID:[A new approach to the analysis of complex chromosomal rearrangements in cell hybrids]. 958 54