Identification of human MutY homolog (hMYH) as a repair enzyme for 2-hydroxyadenine in DNA and detection of multiple forms of hMYH located in nuclei and mitochondria

Nucleic Acids Res. 2000 Mar 15;28(6):1355-64. doi: 10.1093/nar/28.6.1355.

Abstract

An enzyme activity introducing an alkali-labile site at 2-hydroxyadenine (2-OH-A) in double-stranded oligonucleotides was detected in nuclear extracts of Jurkat cells. This activity co-eluted with activities toward adenine paired with guanine and 8-oxo-7,8-dihydroguanine (8-oxoG) as a single peak corresponding to a 55 kDa molecular mass on gel filtration chromatography. Further co-purification was then done. Western blotting revealed that these activities also co-purified with a 52 kDa polypeptide which reacted with antibodies against human MYH (anti-hMYH). Recombinant hMYH has essentially similar activities to the partially purified enzyme. Thus, hMYH is likely to possess both adenine and 2-OH-A DNA glycosylase activities. In nuclear extracts from Jurkat cells, a 52 kDa polypeptide was detected with a small amount of 53 kDa polypeptide, while in mitochondrial extracts a 57 kDa polypeptide was detected using anti-hMYH. With amplification of the 5'-regions of the hMYH cDNA, 10 forms of hMYH transcripts were identified and subgrouped into three types, each with a unique 5' sequence. These hMYH transcripts are likely to encode multiple authentic hMYH polypeptides including the 52, 53 and 57 kDa polypeptides detected in Jurkat cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / metabolism
  • Amino Acid Sequence
  • Blotting, Western
  • Cell Extracts
  • Cell Nucleus / enzymology
  • DNA / chemistry*
  • DNA / genetics
  • DNA / metabolism*
  • DNA Glycosylases*
  • DNA Repair / genetics*
  • Gene Expression Profiling
  • Guanine / analogs & derivatives
  • Guanine / metabolism*
  • HeLa Cells
  • Humans
  • Isoenzymes / chemistry
  • Isoenzymes / genetics
  • Isoenzymes / isolation & purification
  • Isoenzymes / metabolism
  • Jurkat Cells
  • Mitochondria / enzymology
  • Molecular Sequence Data
  • Molecular Weight
  • N-Glycosyl Hydrolases / chemistry*
  • N-Glycosyl Hydrolases / genetics
  • N-Glycosyl Hydrolases / isolation & purification
  • N-Glycosyl Hydrolases / metabolism*
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / isolation & purification
  • Peptides / metabolism
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Substrate Specificity

Substances

  • Cell Extracts
  • Isoenzymes
  • Peptides
  • RNA, Messenger
  • Recombinant Proteins
  • 8-hydroxyguanine
  • Guanine
  • DNA
  • isoguanine
  • DNA Glycosylases
  • N-Glycosyl Hydrolases
  • mutY adenine glycosylase
  • Adenine

Associated data

  • GENBANK/AB032920
  • GENBANK/AB032921
  • GENBANK/AB032922
  • GENBANK/AB032923
  • GENBANK/AB032924
  • GENBANK/AB032925
  • GENBANK/AB032926
  • GENBANK/AB032927
  • GENBANK/AB032928
  • GENBANK/AB032929