Disease relevance of Guanosine, N-methyl-

• The 5'-terminus 7-methylguanosine of vesicular stomatitis virus mRNA is not essential for translation of the mRNA [1].
• The central portion (region P) of the 742-nucleotide noncoding 5' end of poliovirus allows the RNA to initiate protein synthesis in the absence of the usual 5' 7-methylguanosine capping group [2].
• The minor nucleoside 7-methylguanosine occurs in Escherichia coli 16 S ribosomal RNA at a single site [3].
• The 5' end of tobacco mosaic virus (TMV) genomic RNA is capped with 7-methylguanosine [4].
• Both 7-methylguanosine products, m7G5'pppp5'G and m7G5'pppp5'm7G, acted as potent inhibitors of capped brome mosaic virus (BMV) RNA translation in the homologous wheat germ protein synthesis system [5].

High impact information on Guanosine, N-methyl-

• Ribosome binding to reovirus mRNA in protein synthesis requires 5' terminal 7-methylguanosine [6].
• These data support a model in which telomerase RNA is transcribed by RNA polymerase II and 7-methylguanosine-capped, binds the seven Sm proteins, becomes TMG-capped and picks up the other protein subunits [7].
• 7-methylguanosine 5'-monophosphate inhibits protein synthesis in a fractionated, messenger-dependent, reticulocyte cell-free system [8].
• These studies provide evidence that the role of 7-methylguanosine in the mechanism for initiation of eukaryotic mRNA translation may be related to specific recognition of mRNA by initiation factor IF-M3 [8].
• Sequence-nonspecific binding of RNA, recognition of a 7-methylguanosine 5' mRNA cap, and methylation of a nucleic acid backbone are three crucial and ubiquitous events in eukaryotic nucleic acid processing and function [9].

Chemical compound and disease context of Guanosine, N-methyl-

• Tobacco mosaic virus RNA carries 5'-terminal triphosphorylated guanosine blocked by 5'-linked 7-methylguanosine [10].
• Vannielii extracts with S-adenosylmethionine and undermethylated E. coli tRNA revealed active tRNA methyltransferases for formation of methylated residues found in native M. vannielii tRNA, but none for the formation of 7-methylguanosine or ribothymidine [11].

Biological context of Guanosine, N-methyl-

• Here we show that exposure of permeable trypanosome cells to S-adenosyl-L-homocysteine inhibits methylation of the nucleosides adjacent to 7-methylguanosine of newly synthesized SL RNA and prevents utilization of the SL RNA in trans splicing [12].
• Eukaryotic translation initiation factor eIF-4E plays a central role in the recognition of the 7-methylguanosine-containing cap structure of mRNA and the formation of initiation complexes during protein synthesis. eIF-4E exists in both phosphorylated and nonphosphorylated forms, and the primary site of phosphorylation has been identified [13].
• A preliminary study of the alkaline hydrolysis of the 7-methylguanosine residue that occurs at position 47 showed that at least two products are formed instead of only one as usually quoted in the literature [14].
• The terminal 7-methylguanosine is recognized by cap-binding proteins that facilitate key events in gene expression including mRNA processing, transport, and translation [15].
• In greater than 95% of the complexes observed for each type of ribosome, antibody contact was consistent with a single binding site, which places 7-methylguanosine near the junction of the upper one-third and lower two-thirds of the subunit and maximally distant from the platform [3].

Anatomical context of Guanosine, N-methyl-

• The messenger RNA cap-binding protein (CBP) was isolated from human erythrocyte, rabbit erythrocyte, and rabbit reticulocyte lysate by affinity chromatography on 7-methylguanosine 5'-triphosphate-Sepharose [16].
• Inhibition of HeLa cell messenger RNA translation by 7-methylguanosine 5'-monophosphate [17].
• A rate-limiting step during translation initiation in eukaryotic cells involves binding of the initiation factor eIF4E to the 7-methylguanosine-containing cap of mRNAs [18].
• A novel wobble rule found in starfish mitochondria. Presence of 7-methylguanosine at the anticodon wobble position expands decoding capability of tRNA [19].
• Antibodies specific for 7-methylguanosine (m7G) were evaluated for their ability to inhibit the translation of chorion mRNA in a wheat germ, cell-free amino acid incorporating system [20].

Associations of Guanosine, N-methyl- with other chemical compounds

• They are not only eluted specifically, together with snRNP particles, from anti-2,2,7-trimethylguanosine immunoaffinity columns by 7-methylguanosine, they also cofractionate with U5 snRNP during chromatography and, most importantly, in glycerol gradient centrifugation [21].
• The 7-methylguanosine cap, stem-loops I and II, the lariat branch site recognition sequence, the conserved Sm domain, and several other regions throughout the 5' end of U2 RNA have no apparent role in the 3' processing reaction [22].
• 7-Methylguanosine-dependent inhibition of globin mRNA translation by methylglyoxal [23].
• Prior to trans-splicing, the mini-exon donor RNA is capped by the addition of a (5'-5') triphosphate-linked 7-methylguanosine, followed by modification of the first four transcribed nucleotides [24].
• A novel guanine-guanine base pairing: crystal structure of a complex between 7-methylguanosine and its iodide [25].

Gene context of Guanosine, N-methyl-

• IFE-3, the most closely related to mammalian eIF4E-1, binds only 7-methylguanosine caps and is essential for viability [26].
• Backbone resonance assignment of human eukaryotic translation initiation factor 4E (eIF4E) in complex with 7-methylguanosine diphosphate (m7GDP) and a 17-amino acid peptide derived from human eIF4GII [27].
• Trm11p and Trm112p are both required for the formation of 2-methylguanosine at position 10 in yeast tRNA [28].
• The CBC represents a 20- and 80-kDa heterodimer (the subunits independently referred to as CBP20 and CBP80, respectively) that binds the 7-methylguanosine cap on RNAs transcribed by RNA polymerase II [29].
• Tgs1 is the enzyme responsible for converting 7-methylguanosine RNA caps to the 2,2,7-trimethylguanosine cap structures of small nuclear and small nucleolar RNAs [30].

Analytical, diagnostic and therapeutic context of Guanosine, N-methyl-

• 1. A phosphorylated cap-binding protein was substantially enriched from lysates of control or TNF-alpha-treated ME-180 cells by affinity chromatography with 7-methylguanosine 5'-triphosphate-Sepharose [31].
• Electron microscopy of antibody-subunit complexes placed the methyladenosine residue in a position that is essentially indistinguishable from that of 7-methylguanosine [32].
• To solve this enigma, the mt tRNA GCUser was purified, and sequence determination in combination with electrospray liquid chromatography/mass spectrometry revealed that 7-methylguanosine is located at the first position of the anticodon [19].
• Ribosome structure. Localization of 7-methylguanosine in the small subunits of Escherichia coli and chloroplast ribosomes by immunoelectron microscopy [3].
• A competitive ELISA detecting 7-methylguanosine adduct induced by N-nitrosodimethylamine exposure [33].

References