Inhibitory effects of acidic phospholipids on the binding of origin-recognition complex to origin DNA.
Origin-recognition complex (ORC), a candidate initiator of chromosomal DNA replication in eukaryotes, shares certain biochemical characteristics with DnaA, the initiator of chromosomal DNA replication in prokaryotes. These similarities include origin-specific DNA binding, ATP binding and ATPase activity. DnaA interacts with acidic phospholipids, such as cardiolipin, and its activity is regulated by these phospholipids. In this study, we examined whether Saccharomyces cerevisiae ORC also interacts with phospholipids. Among the various phospholipids tested, ORC was found to bind specifically to cardiolipin. This binding was inhibited by excess concentrations of salts but unaffected by ATP, adenosine 5'-[gamma-thio]triphosphate or the origin DNA. Cardiolipin weakly inhibited the ATP-binding activity of ORC, whereas it strongly inhibited ORC binding to origin DNA. Acidic phospholipids other than cardiolipin (phosphatidylglycerol and phosphatidylinositol) weakly inhibited ORC binding to origin DNA. Furthermore, total phospholipids extracted from yeast nuclear membranes inhibited ORC binding to origin DNA. We consider that phospholipids may modulate initiation of DNA replication in eukaryotes in a similar manner to that found in prokaryotes.
Lee
Jong-Ryul
JR
Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1, Tsushima-naka, Okayama 700-8530, Japan.
Makise
Masaki
M
Takenaka
Hitomi
H
Takahashi
Naoko
N
Yamaguchi
Yoshihiro
Y
Tsuchiya
Tomofusa
T
Mizushima
Tohru
T
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D016367:Baculoviridae; D001665:Binding Sites; D002308:Cardiolipins / Q000494:pharmacology; D002460:Cell Line; D004247:DNA / Q000187:drug effects / Q000235:genetics*; D004261:DNA Replication / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009685:Nuclear Envelope / Q000187:drug effects / Q000378:metabolism; D051738:Origin Recognition Complex; D010743:Phospholipids / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D018411:Spodoptera; D014162:Transfection
D002308:Cardiolipins; D004268:DNA-Binding Proteins; D051738:Origin Recognition Complex; D010743:Phospholipids; D011994:Recombinant Proteins; D004247:DNA; D000251:Adenosine Triphosphatases