Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.25 (triphosphatase)
 1,529 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection of cells with herpes simplex virus type 1 (HSV-1) induces high levels of deoxypyrimidine triphosphatase. The majority of the enzyme activity is found in infected cell nuclei. A similar activity is induced by HSV type 2 (HSV-2) which, in contrast to the HSV-1 enzyme, fractionates to more than 99% in the soluble cytoplasmic extract. Of a series of temperature-sensitive mutants of HSV-1 studied, only the immediate-early mutants in complementation group 1-2 (strain 17 mutants tsD and tsK and strain KOS mutant tsB2) induced reduced levels of triphosphatase at nonpermissive temperature. Of a series of temperature-sensitive mutants of HSV-2 strain HG52, ts9 and ts13 failed to induce wild-type levels of the enzyme at nonpermissive temperature; ts9 was the most defective mutant with regard to triphosphatase expression of both herpes simplex virus serotypes. After shift-up from permissive to nonpermissive temperature, triphosphatase activity in cells infected with ts9 decreased rapidly, whereas all other mutants continued to exhibit enzyme levels comparable with controls kept at the permissive temperature. The type 1-specific nuclear expression of the triphosphatase was mapped physically by the use of HSV-1 x HSV-2 intertypic recombinants, based on enzyme levels different by more than two orders of magnitude found in nuclei of HSV-1- and HSV-2-infected cells. The locus for the type-specific expression maps between 0.67 and 0.68 fractional length on the HSV genome.
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PMID:Control of expression of the herpes simplex virus-induced deoxypyrimidine triphosphatase in cells infected with mutants of herpes simplex virus types 1 and 2 and intertypic recombinants. 612 30

The baculovirus Autographa californica nucleopolyhedrovirus encodes two proteins with RNA triphosphatase activity. Late expression factor LEF-4, which is an essential gene, is a component of the RNA polymerase and also encodes the RNA capping enzyme guanylyltransferase. PTP/BVP is also an RNA triphosphatase, but is not essential for viral replication, possibly because its activity is redundant to that of LEF-4. To elucidate the role of these proteins in mRNA cap formation, a mutant virus that lacked both RNA triphosphatase activities was constructed. Infection studies revealed that the double-mutant virus was viable and normal with respect to the production of budded virus. Pulse-labeling studies and immunoblot analyses showed that late gene expression in the double mutant was equivalent to that in the wild type, while polyhedrin expression was slightly reduced. Direct analysis of the mRNA cap structure indicated no alteration of cap processing in the double mutant. Together, these results reveal that baculoviruses replicate and express their late genes at normal levels in the absence of its two different types of RNA triphosphatases.
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PMID:Roles of LEF-4 and PTP/BVP RNA triphosphatases in processing of baculovirus late mRNAs. 1838 32