JaLCDOI 10.18926/AMO/30516
FullText URL fulltext.pdf
Author Tan, Yunshan| Nakagawa, Yuko| Akiyama, Kosuke| Wakabayashi, Hajime| Sarker, Altaf H.| Seki, Shuji|
Abstract <p>APEX nuclease is a mammalian DNA repair enzyme having apurinic/apyrimidinic (AP) endonuclease, 3'-5'-exonuclease, DNA 3' repair diesterase and DNA 3'-phosphatase activities. It is also a redox factor (Ref-1), stimulating DNA binding activity of AP-1 binding proteins such as Fos and Jun. In the present paper, a cDNA for the enzyme was isolated from a rat brain cDNA library using mouse Apex cDNA as a probe and sequenced. The rat Apex cDNA was 1221 nucleotides (nt) long, with a 951-nt coding region. The amino acid sequence of rat APEX nuclease has 98.4% identity with mouse APEX nuclease. Using the rat Apex cDNA as a probe for Northern blot analysis, the size of rat Apex mRNA was shown to be approximately 1.5 kb. Its expression was compared in 9 rat organs on postnatal days 7 and 28. Although Apex mRNA was expressed ubiquitously, the levels varied significantly, suggesting organ- or tissue-specific expression of the Apex gene. The highest level was observed in the testis, relatively high levels in the thymus, spleen, kidney and brain, and the lowest level in the liver. The level of expression at postnatal day 28, with the exception of the testis, was almost the same as or lower in respective organs than that at postnatal day 7. Postnatal developmental changes of Apex mRNA expression in the testis and thymus were further studied. The expression in testis was markedly increased on postnatal days 21 and 28. The expression in thymus increased once at postnatal day 14, and then decreased. The developmental changes of Apex mRNA expression in testis and thymus suggest that APEX nuclease is involved in processes such as recombinational events.</p>
Keywords Apurinic/apyrimidinic endonclease; APEX nuclease; Repair enzyme; Apex mRNA; Northen blot; developument; testis; rat
Amo Type Article
Published Date 1996-02
Publication Title Acta Medica Okayama
Volume volume50
Issue issue1
Publisher Okayama University Medical School
Start Page 53
End Page 60
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 8701782
Web of Sience KeyUT A1996TY06000008
JaLCDOI 10.18926/AMO/30505
FullText URL fulltext.pdf
Author Wakabayashi, Hajime| Tsuji, Takao| Seki, Shuji|
Abstract <p>&#60;P&#62;We purified an apurinic/apyrimidinic (AP) endonuclease from mouse ascites sarcoma (SR-C3H/He) cells. The enzyme showed nicking activity on acid-depurinated DNA but not on untreated, intact DNA. It also showed priming activity for DNA polymerase on both acid-depurinated and bleomycin-damaged DNA. The priming activity on bleomycin-damaged DNA was two times higher than that on an acid-depurinated DNA. The enzymatic properties indicate that the enzyme is a class II AP endonuclease having DNA 3' repair diesterase activity. The purified enzyme has a molecular weight of 39,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimal pH for AP endonuclease activity was 8.0 in 50 mM Tris-HCl buffer. The AP endonuclease activity depended on divalent cation such as Mg2+ and Co2+ ions, and was inhibited by 2 mM EDTA with no addition of the divalent cation. An appropriate concentration of sodium or potassium salt stimulated the activity. Partial digestion of the AP endonuclease with Staphylococcus aureus V8 protease produced 4 major peptide fragments which may be used for protein sequencing.&#60;/P&#62;</p>
Keywords AP endonuclease DNA 3' repair diesterase DNA repair enzyme mouse ascites sarcoma cells
Amo Type Article
Published Date 1996-06
Publication Title Acta Medica Okayama
Volume volume50
Issue issue3
Publisher Okayama University Medical School
Start Page 131
End Page 137
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 8805852
Web of Sience KeyUT A1996UU60400003