A positive association between intake of calcium channel blockers and psoriasis has been observed recently. Intake of blockers of voltage-gated calcium ion channels is associated with outbreaks of psoriasis after a latent period in patients with and without a previous family history of psoriasis. This suggests that interfering with calcium influx may trigger psoriasis. Calcium influx also occur...

Cyclic guanosine 3',5'-monophosphate inhibits the synthesis of beta-galactosidase and tryptophanase in cultures of Escherichia coli growing in minimal media with glucose or glycerol as the carbon source. Cyclic guanosine 3',5'-monophosphate acts at the transcriptional level in the lac operon, it exerts its action at the promoter site of the operon, and requires the presence of functional cyclic...

The phosphorylation of nucleosides (adenosine, guanosine, cytidine, and uridine) and nucleotides (adenosine 5'-monophosphate, guanosine 5'-monophosphate, cytidine 5'-monophosphate and uridine 5'-monophosphate) has been achieved using inorganic monoimido-cyclo-triphosphate (MCTP, Na(3)P(3)O(8)NH) in aqueous solution. In this reaction, the 2'-OH or 3'-OH group of the beta-D-ribofuranose unit was ...

Purified human reovirus contains RNA methylase activity in addition to an RNA polymerase. Virions incubated under appropriate conditions in the presence of S-adenosyl-L-methionine synthesize mRNA that is specifically methylated in the 5'-terminal guanosine. Alkaline digestion of the methylated RNA released a 5'-terminal dinucleotide, ppG'pCp, indicating that the guanosine contains 2'-O-methylri...

Several supramolecular architectures generated by guanosine derivatives are described. The research started from the fortuitous observation of a lyotropic behavior exhibited by a guanylic nucleotide in water. This observation stimulated extensive research on several natural and lipophilic guanosine derivatives which self-assemble in different architectures (discs, ribbons, helices...), accordin...

An enzyme fraction from the green alga Chlorella pyrenoidosa that catalyzes the reversible epimerization of guanosine B’diphosphate D-mannose to guanosine 5’-diphosphate L-galactose brings about the incorporation of tritium from tritium-labeled water into the hexosyl moieties of those sugar nucleotides. The hexoses were degraded by periodate oxidation whereby the tritium was found to be equally...

Guanine nucleotide-binding proteins regulate a variety of processes, including sensual perception, protein synthesis, various transport processes, and cell growth and differentiation. They act as molecular switches and timers that cycle between inactive guanosine diphosphate (GDP)-bound and active guanosine triphosphate (GTP)-bound states. Recent structural studies show that the switch apparatu...

The Tetrahymena intron is an RNA catalyst, or ribozyme. As part of its self-splicing reaction, this ribozyme catalyzes phosphoryl transfer between guanosine and a substrate RNA strand. Here we report the refined crystal structure of an active Tetrahymena ribozyme in the absence of its RNA substrate at 3.8 A resolution. The 3'-terminal guanosine (omegaG), which serves as the attacking group for ...

The 5' triphosphates of the methylated nucleoside analogs 3'-O-methyl adenosine and 3'-O-methyl guanosine are RNA chain terminators in vitro. However, anticellular or antiviral effects of 3'-O-methylated nucleosides or nucleotides have not been investigated. This is presumably because of the assumption that cellular kinases will be unable to phosphorylate the nucleosides. We report here that co...

A reduction in the incident light intensity has been used to elicit guanosine 5'-diphosphate 3'-diphosphate accumulation in cyanobacteria. Inhibitors of photophosphorylation, 2,4-dinitrophenol, and carbonyl cyanide-m-chlorophenyl hydrazone elicited accumulation in three species of cyanobacteria when they were grown on dinitrogen or nitrate, but not in cultures grown on ammonium or glutamine. Ac...