AlkB restores the biological function of mRNA and tRNA inactivated by chemical methylation.
Deleterious 1-methyladenine (1-meA) and 3-methylcytosine (3-meC) lesions are introduced into nucleic acids by methylating agents. It was recently demonstrated that the E. coli AlkB protein and a human homolog, hABH3, can demethylate these lesions both in DNA and RNA. To elucidate the biological significance of the RNA repair, we have tested whether such repair can rescue the function of chemically methylated RNA. We demonstrate that a methylation-induced block in translation of an mRNA can be readily relieved by treatment with AlkB and hABH3 prior to translation. Furthermore, we show that chemical methylation of tRNAPhe inhibits aminoacylation and translation, but that the inhibition can be reversed by AlkB and hABH3. AlkB-mediated repair of 1-meA in tRNA was also observed in E. coli in vivo. Our data demonstrate that AlkB proteins can mediate functional recovery of RNA exposed to methylation damage, supporting the notion that RNA repair is important.
Centre for Molecular Biology and Neuroscience and Institute of Medical Microbiology, Rikshospitalet University Hospital, NO-0027 Oslo, Norway.
Rune
R
Ougland
Chun-Mei
CM
Zhang
Aivar
A
Liiv
Rune F
RF
Johansen
Erling
E
Seeberg
Ya-Ming
YM
Hou
Jaanus
J
Remme
Pål Ø
PØ
Falnes
D000071498:AlkB Homolog 1, Histone H2a Dioxygenase; D000071500:AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000378:metabolism; D049308:Dioxygenases; D029968:Escherichia coli Proteins / Q000378:metabolism*; D006801:Humans; D008745:Methylation; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*; D017423:Sequence Analysis, RNA
D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D012343:RNA, Transfer; D006899:Mixed Function Oxygenases; D049308:Dioxygenases; C486439:ALKBH3 protein, human; D000071500:AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; C466427:AlkB protein, E coli; C499236:ALKBH1 protein, human; D000071498:AlkB Homolog 1, Histone H2a Dioxygenase; D045643:DNA Repair Enzymes