TY - JOUR
T1 - Nucleotide Methylation Patterns in Eukaryotic mRNA
AU - Rottman, Fritz M.
AU - Desrosiers, Ronald C.
AU - Friderici, Karen
PY - 1977/1/1
Y1 - 1977/1/1
N2 - The use of enzymes for selective hydrolysis, coupled with high-resolution liquid chromatography for assay of products, provides an efficient means of determining the specific patterns of methylation in eukaryotic mRNA molecules. Continuous labeling with levels of L-[methyl-3H] methionine permits normal growth of Novikoff cells to examine the methylation of specific sites of cytoplasmic mRNA as a function of time. The main site of cytoplasmic mRNA labeling is at the second position (N'') of the 5'-terminal sequence. Data obtained by comparing methylnucleoside composition of these sequences and the ratio of doubly to singly O-methylated termini as a function of labeling time is consistent with a model in which m7G, N'm and the m6A located in the mRNA molecule are all products of nuclear methylation events. Subsequently there is a cytoplasmic methylation of some singly O-methylated structures at the second (N'') position yielding the doubly O-methylated structure. The kinetics of methyl labeling and the changing composition within the caps show a distinct pattern, possibly reflecting a selection or enrichment of a stable class of mRNA molecules, many of which contain the doubly labeled structure at their 5'-terminus and are of smaller size.
AB - The use of enzymes for selective hydrolysis, coupled with high-resolution liquid chromatography for assay of products, provides an efficient means of determining the specific patterns of methylation in eukaryotic mRNA molecules. Continuous labeling with levels of L-[methyl-3H] methionine permits normal growth of Novikoff cells to examine the methylation of specific sites of cytoplasmic mRNA as a function of time. The main site of cytoplasmic mRNA labeling is at the second position (N'') of the 5'-terminal sequence. Data obtained by comparing methylnucleoside composition of these sequences and the ratio of doubly to singly O-methylated termini as a function of labeling time is consistent with a model in which m7G, N'm and the m6A located in the mRNA molecule are all products of nuclear methylation events. Subsequently there is a cytoplasmic methylation of some singly O-methylated structures at the second (N'') position yielding the doubly O-methylated structure. The kinetics of methyl labeling and the changing composition within the caps show a distinct pattern, possibly reflecting a selection or enrichment of a stable class of mRNA molecules, many of which contain the doubly labeled structure at their 5'-terminus and are of smaller size.
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U2 - 10.1016/S0079-6603(08)60906-X
DO - 10.1016/S0079-6603(08)60906-X
M3 - Article
C2 - 190642
AN - SCOPUS:0017278383
VL - 19
SP - 21
EP - 38
JO - Progress in Molecular Biology and Translational Science
JF - Progress in Molecular Biology and Translational Science
SN - 1877-1173
IS - C
ER -