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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
20
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pubmed:dateCreated |
1976-1-2
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pubmed:abstractText |
KOH digestion of methyl-labeled poly(A)+ mRNA purified by (dT)-cellulose chromatography produced mononucleotide and multiple peaks of a large oligonucleotide (-6 to -8 charge) when separated on the basis of charge by Pellionex-WAX high-speed liquid chromatography in 7 M urea. Heat denaturation of the RNA before application to (dT)-cellulose was required to release contaminants (mostly 18S rRNA) that persisted even after repeated binding to (dT)-cellulose at room temperature. Analysis of the purified poly(A)+ mRNA by enzyme digestion, acid hydrolysis, and a variety of chromatographic techniques has shown that the monucleotide (53%) is due entirely to N6-methyladenosine. The large oligonucleotides (47%) were found to contain 7-methylguanosine and the 2'-0-methyl derivatives of all four nucleosides. No radioactivity was found associated with the poly(A) segment. Periodate oxidation of the mRNA followed by beta elimination released only labeled 7-methylguanine consistent with a blocked 5' terminus containing an unusual 5'-5' bond. Alkaline phosphatase treatment of intact mRNA had no effect on the migration of the KOH produced oligonucleotides on Pellionex-WAX. When RNA from which 7-methylguanine was removed by beta elimination was used for the phosphatase treatment, distinct dinucleotides (NmpNp) and trinucleotides (NmpNmpNp) occurred after KOH hydrolysis and Pellionex-WAX chromatography. Thus Novikoff hepatoma poly(A)+ mRNA molecules can contain either one or two 2'-0-methylnucleotides linked by a 5'-5' bond to a terminal 7-methylguanosine and the 2'-0-methylation can occur with any of the four nucleotides. The 5' terminus may be represented by m7G5'ppp5' (Nmp)lor2Np, a general structure proposed earlier as a possible 5' terminus for all eucaryotic mRNA molecules (Rottman, F., Shatkin, A., and Perry, R. (1974), Cell 3, 197). The composition analyses indicate that there are 3.0 N6-methyladenosine residues, 1.0 7-methylguanosine residue, and 1.7 2'-0-methylnucleoside residues per average mRNA molecule.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
7
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pubmed:volume |
14
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
4367-74
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:169893-Animals,
pubmed-meshheading:169893-Base Sequence,
pubmed-meshheading:169893-Carcinoma, Hepatocellular,
pubmed-meshheading:169893-Cells, Cultured,
pubmed-meshheading:169893-Chromatography, Affinity,
pubmed-meshheading:169893-Chromatography, High Pressure Liquid,
pubmed-meshheading:169893-Liver Neoplasms,
pubmed-meshheading:169893-Methylation,
pubmed-meshheading:169893-Neoplasms, Experimental,
pubmed-meshheading:169893-Poly A,
pubmed-meshheading:169893-RNA, Messenger,
pubmed-meshheading:169893-RNA, Neoplasm,
pubmed-meshheading:169893-Rats,
pubmed-meshheading:169893-Waxes
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pubmed:year |
1975
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pubmed:articleTitle |
Characterization of Novikoff hepatoma mRNA methylation and heterogeneity in the methylated 5' terminus.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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