7-methylguanosine and 1-methyladenosine

The messenger RNA (mRNA) methylations in mammalian cells have been found to contain N

Topics: Adenosine; Aldehydes; Amines; Base Sequence; Cell Line; Epigenesis, Genetic; Gene Expression Regulation; Guanosine; Humans; Methylation; RNA Processing, Post-Transcriptional; RNA, Messenger; Single Molecule Imaging; Staining and Labeling

RNA modifications are recently emerged epigenetic modifications. These diverse RNA modifications have been shown to regulate multiple biological processes, including development. RNA modifications are dynamically controlled by the "writers, erasers, and readers", where RNA modifying proteins are able to add, remove, and recognize specific chemical modification groups on RNAs. However, little is known about the ontogenic expression of these RNA modifying proteins in various organs, such as liver. In the present study, the hepatic mRNA expression of selected RNA modifying proteins involve in m6A, m1A, m5C, hm5C, m7G, and Ψ modifications was analyzed using the RNA-seq technique. Liver samples were collected from male C57BL/6 mice at several ages from prenatal through neonatal, infant, child to young adult. Results showed that most of the RNA modifying proteins were highly expressed in prenatal mouse liver with a dramatic drop at birth. After birth, most of the RNA modifying proteins showed a downregulation trend during liver maturation. Moreover, the RNA modifying proteins that belong to the same enzyme family were expressed at different abundances at the same ages in mouse liver. In conclusion, this study unveils that the mRNA expression of RNA modifying proteins follows specific ontogenic expression patterns in mice liver during maturation. These data indicated that the changes in expression of RNA modifying proteins might have a potential role to regulate gene expression in liver through alteration of RNA modification status.

Topics: 5-Methylcytosine; Adenosine; AlkB Homolog 5, RNA Demethylase; Animals; Animals, Newborn; Embryo, Mammalian; Epigenesis, Genetic; Gene Expression Regulation, Developmental; Guanosine; Liver; Male; Methyltransferases; Mice; Pseudouridine; RNA Helicases; RNA Processing, Post-Transcriptional; RNA-Seq; RNA, Messenger

The aim of this study was to investigate and compare the levels of concentration of modified nucleosides in the urine of autistic and healthy children. The compounds have never been analyzed before. The levels of nucleosides in the urine of both groups were determined by validated high performance liquid chromatography coupled to mass spectrometry (LC-MS/MS) method using multiple reaction monitoring (MRM) mode. Chromatographic separation was achieved with HILIC column and tubercidin was used as the internal standard for the quantification of urinary nucleosides. The within run accuracy and precision ranged from 89 to 106% and from 0.8% to 4.9%, respectively. Lower levels of O-methylguanosine, 7-methylguanosine, 1-methyladenosine, 1-methylguanine, 7-methylguanine and 3-methyladenine in the urine of 22 children with autism, aged 3 to 16 were observed. The differences were not observed in 20 healthy volunteers, in a similar age group. These findings show that modified nucleosides there are metabolic disturbances and nutritional deficiencies in autistic children.

Topics: Adenine; Adenosine; Adolescent; Autistic Disorder; Child; Child, Preschool; Chromatography, Liquid; Female; Guanine; Guanosine; Humans; Male; Mass Spectrometry

The levels of the five methylated nucleosides pseudouridine (psi-Urd), 1-methyladenosine (1-MeAdo), 4 acetylcytidine (4-AcCyd), 1 methylinosine (1-Melno) and 7 methylguanosine (7-MeGuo) resulting from RNA degradation were examined in the urine of rheumatoid arthritis (RA) patients. Of these five, 1-MeAdo and psi-Urd were correlated with the active phase of the disease, while two others (4-AcCyd and 1-Melno), which require further evaluation, appeared to be linked to the prognosis of the disease. As RNA turnover is closely associated with cell proliferation, including that of lymphocytes in RA, there may be a hitherto unsuspected benefit in measuring 1-MeAdo and psi-Urd as biochemical markers of RA disease activity.

Topics: Adenosine; Aged; Arthritis, Rheumatoid; Biomarkers; Cytidine; Female; Follow-Up Studies; Guanosine; Humans; Inosine; Male; Middle Aged; Nucleosides; Pseudouridine; RNA Caps; RNA, Ribosomal; RNA, Transfer

The 1H, 13C, and 15N NMR spectra of neutral and protonated forms of the nucleosides 1-methyladenosine (m1A), 7-methylguanosine (m7G) and ethenoadenosine (EA), as a model compound, have been analyzed in order to assign the site of protonation in m1A and m7G. Protonation of these nucleosides occurs in the pyrimidine ring of m1A and EA and in the imidazole ring of m7G, with the charge being distributed rather than localized. Structural differences for both m1A and m7G were observed in solution and compared with those existing in the crystal state of monomers as well as in tRNA where these nucleosides occur quite often. The protonated nucleoside structures in solution compared favorably in sugar pucker and glycosidic bond conformations with x-ray crystallographic data. Methyl group carbon chemical shifts of the protonated mononucleosides corresponded to those of the methyls of the respective nucleosides in native tRNA structures. Therefore, the tRNA methyl group carbon chemical shifts are indicative of fully protonated nucleosides in the native, three dimensional structure of the nucleic acid.

Topics: Adenosine; Dimethyl Sulfoxide; Guanosine; Magnetic Resonance Spectroscopy; Nucleic Acid Conformation; Protons; Spectrophotometry, Infrared; Trifluoroacetic Acid

We describe the selective analysis of N-methylated ribonucleosides, i.e., N1-methyl adenosine (m1Ado) and N7-methyl guanosine (m7Guo) in the presence of other nucleosides in urine. m1Ado as well as m7Guo were characterized by use of chromatographic techniques including substance specific chemical reactions.

Topics: Adenosine; Adult; Chemical Phenomena; Chemistry; Child; Child, Preschool; Chromatography, High Pressure Liquid; Female; Guanosine; Humans; Infant; Male; Nucleosides; Spectrophotometry, Ultraviolet