Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphorylase kinase is a multimeric enzyme of composition (alpha, beta, gamma, delta)4 whose catalytic activity resides in the gamma-subunit. As an approach to understand further its regulation, a cDNA for the gamma-subunit of phosphorylase kinase (gamma PhK) has been cloned into a mammalian expression vector behind the mouse metallothionein-1 promoter. NIH 3T3 cells were co-transfected with this construct (pEV gamma PhK) and pSV2neo, G418-resistant clones were selected, and several were found to have stably incorporated the gamma-subunit cDNA into their genomic DNA. Phosphorylase kinase activity was clearly present in extracts from cultures of pEV gamma PhK-transformed cells and increased several-fold after 24 h of incubation with Zn2+, whereas it was undetectable in the parent 3T3 cells. A significant, but variable, proportion (15-70%) of the activity was Ca2+-dependent. We conclude that the phosphorylase kinase activity expressed by the cells transformed with pEV gamma PhK is due to free gamma-subunit and gamma-subunit associated with cellular calmodulin, which replaces the delta-subunit normally associated with the gamma-subunit in the holoenzyme.
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PMID:Expression of a cDNA for the catalytic subunit of skeletal-muscle phosphorylase kinase in transfected 3T3 cells. 248 39

True gamma or gamma 2 genes, unlike alpha, beta, and gamma 1 (beta gamma) genes of herpes simplex virus 1 (HSV-1), stringently require viral DNA synthesis for their expression. We report that gamma 2 genes resident in cells were induced in trans by infection with HSV-1 but that the induction did not require amplification of either the resident gene or the infecting viral genome. Specifically, to test the hypothesis that expression of these genes is amplification dependent, we constructed two sets of gamma 2-thymidine kinase (TK) chimeric genes. The first (pRB3038) consisted of the promoter-regulatory region and a portion of 5'-transcribed noncoding region of the domain of a gamma 2 gene identified by Hall et al. (J. Virol. 43:594-607) in the HSV-1(F) BamHI fragment D' to the 5'-transcribed noncoding and coding regions of the TK gene. The second (pRB3048) contained, in addition, an origin of HSV-1 DNA replication. Cells transfected with either the first or second construct and selected for the TK+ phenotype were then tested for TK induction after superinfection with HSV-1(F) delta 305, containing a deletion in the coding sequences of the TK gene, and viruses containing, in addition, a ts lesion in the alpha 4 regulatory protein (ts502 delta 305) or in the beta 8 major DNA-binding protein (tsHA1 delta 305). The results were as follows: induction by infection with TK- virus of chimeric TK genes with or without an origin of DNA replication was dependent on functional alpha 4 protein but not on viral DNA synthesis; the resident chimeric gene in cells selected for G418 (neomycin) resistance was regulated in the same fashion; the chimeric gene recombined into the viral DNA was regulated as a gamma 2 gene in that its expression in infected cells was dependent on viral DNA synthesis; the gamma 2-chimeric genes resident in the host and in viral genomes were transcribed from the donor BamHI fragment D' containing the promoter-regulatory domain of the gamma 2 gene. The significance of the differential regulation of gamma 2 genes in the environments of host and viral genomes by viral trans-acting factors is discussed.
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PMID:gamma 2-Thymidine kinase chimeras are identically transcribed but regulated a gamma 2 genes in herpes simplex virus genomes and as beta genes in cell genomes. 298 55

A predominant form of the GABAA/benzodiazepine receptor-Cl- channel complex is believed to consist of three different 48-55 kDa subunits (alpha, beta, gamma) with unknown stoichiometry. Plasmids containing the rat GABAA receptor cDNAs coding for alpha 1, beta 2, and gamma 2 were co-transfected, along with a plasmid encoding G418 resistance, into human embryonic kidney cells previously transformed with Adenovirus 5 (HEK-293) [J. Gen. Virol., 36 (1977) 59-72]. Four percent of the G418 resistant colonies were found to express mRNA for all three of the GABAA subunits constitutively. A single cell clone derived from one of the alpha 1 beta 2 gamma 2 expressors has demonstrated stable electrophysiological characteristics over 25 passages. The GABA-activated Cl- current in this cell line is blocked by picrotoxin and bicuculline, and is modulated by a variety of agonist and inverse agonist ligands including diazepam, Ro 154513, zolpidem, and beta-CCE. The cell line has been used successfully over a 12-month period as a screen for novel drugs modulating GABA-mediated polarization of neuronal cells.
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PMID:Stable expression of cloned rat GABAA receptor subunits in a human kidney cell line. 768 50