Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isolated restriction endonuclease fragments of the herpes simplex virus type 1 (HSV-1) genome were introduced into hamster embryo cells to identify DNA sequences capable to transforming the cells with respect to acquisition of properties correlated with tumorigenicity. One of the fragments generated by cleavage of HSV-1 DNA with the restriction endonuclease Xba I was found to induce transformation at a frequency of about 10 colonies per quantity of fragment recovered from 1 microgram of uncut DNA; fractions containing the other Xba I fragments failed to induce transformation reproducibly, although occasional colonies were detected. The fragment with transforming activity (Xba I-F) is 15.5 X 10(6) daltons in molecular weight and is located between 0.30 and 0.45 map units on the HSV-1 genome. The Xba I-F transformants obtained were selected for their ability to replicate in low concentrations of serum; in addition, they were found to attain high saturation densities in the presence of 10% serum and to form colonies in semisolid medium. Moreover, the transformed cells produced at least one of the viral gene products (a membrane glycoprotein) encoded in the fragment used for transformation, indicating not only that viral DNA was incorporated into the cells, but also that viral genes were expressed.
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PMID:Transformation of hamster embryo fibroblasts by a specific fragment of the herpes simplex virus genome. 21 18

A novel lentivirus was isolated from South African sheep with experimentally transmitted lung adenocarcinoma. Similar to visna virus and caprine arthritis encephalitis virus, this new strain induced cytopathic effects on ovine plexus choroid cultures. In contrast to a recent Israeli isolate from sheep with adenocarcinoma, the South African lentivirus could not transform fibroblast cultures. The antigenic relatedness between the new isolate and visna virus was assessed by immunoprecipitation of radiolabeled viral proteins, using monospecific antisera against visna virus proteins. The results indicate that the new virus contains four major structural proteins of sizes similar to those of visna virus (i.e., gp135, p30, p16, and p14) and have some common antigenic determinants (about 90% in the major core antigen p30). However, the nucleotidic sequences of the novel lentivirus were found to be only 16.5 to 27.4% homologous to visna virus and 8.3 to 15% homologous to caprine arthritis encephalitis virus, by means of liquid hybridization under stringent conditions. The genetic divergence indicated by this last result was confirmed by the dissimilar restriction endonuclease cleavage map of the new virus in comparison to those of visna virus and three caprine arthritis encephalitis virus strains. The demonstration of a third type of ovine lentivirus supports the concept of an important genetic variation among the lentiviruses infecting one animal species.
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PMID:Characteristics of a novel lentivirus derived from South African sheep with pulmonary adenocarcinoma (jaagsiekte). 243 95

We isolated and characterized two spontaneous, weakly leukemogenic mutants of Rauscher spleen focus-forming virus (R-SFFV) that contain mutations in nonoverlapping regions of the membrane envelope (env) glycoprotein gene. As reported previously (M. Ruta and D. Kabat, J. Virol. 35:844-853, 1980), the replication-defective R-SFFV encodes a membrane glycoprotein with an apparent Mr of 54,000 (gp54) which is structurally and immunologically related to the membrane envelope glycoproteins of dual-tropic murine leukemia viruses. Mutant R-SFFV clones 3-25 and 4-3 encode abnormally sized gp54-related glycoproteins with apparent Mrs of 52,000 (gp52) and 45,000 (gp45), respectively. Northern and Southern blot analyses of the mutant R-SFFV nucleic acids indicated that an insertion has occurred in the 3-25 env gene and that a deletion has occurred in the 4-3 env gene. Furthermore, restriction endonuclease analyses and comparisons of the fragmentation patterns of the wild-type and mutant glycoproteins generated by partial proteolysis with Staphylococcus aureus V8 protease indicated that the mutations affect nonoverlapping domains of the envelope glycoprotein (amino-terminal fragment affected in 3-25 glycoprotein and carboxyl-terminal fragment affected in 4-3 glycoprotein). Glycosylation inhibition studies indicated that the reduced size of gp52 is caused at least partly by loss of an asparagine-linked oligosaccharide. In addition, these mutant viruses have dramatically reduced leukemogenicities compared with wild-type R-SFFV. We conclude that the gp54 structural gene is required for initiation or amplification of the splenic erythroblast hyperplasia which characterizes the preleukemic phase of Rauscher disease.
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PMID:Reduced leukemogenicity caused by mutations in the membrane glycoprotein gene of Rauscher spleen focus-forming virus. 631 40

Kell, a 93 kDa type II membrane glycoprotein, and XK, a 444 amino acid multi-pass membrane protein, are blood group proteins that exist as a disulfide-bonded complex on human red cells. The mechanism of Kell/XK assembly was studied in transfected COS cells co-expressing Kell and XK proteins. Time course studies combined with endonuclease-H treatment and cell fractionation showed that Kell and XK are assembled in the endoplasmic reticulum. At later times the Kell component of the complex was not cleaved by endonuclease-H, indicating N-linked oligosaccharide processing and transport of the complex to a Golgi and/or a post-Golgi cell fraction. Surface-labeling of transfected COS cells, expressing both Kell and XK, demonstrated that the Kell/XK complex travels to the plasma membrane. XK expressed in the absence of Kell was also transported to the cell surface indicating that linkage of Kell and XK is not obligatory for cell surface expression.
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PMID:Intracellular assembly of Kell and XK blood group proteins. 1055 84