Abstract
Origin Recognition Complex (ORC) is a candidate initiator of chromosomal DNA replication in eukaryotes. We recently reported that cardiolipin inhibits the interaction of Origin Recognition Complex ORC with origin DNA, as is the case of DnaA, the initiator of chromosomal DNA replication in prokaryotes. We report here that another acidic phospholipid, phosphatidylglycerol (PG), also inhibits the interaction. Synthetic PG with only unsaturated fatty acids inhibits ORC-binding to origin DNA more strongly than PG with only saturated fatty acids. On the other hand, phosphatidylcholine (neutral phospholipid) does not affect the ORC-origin interaction, regardless of the presence of saturated or unsaturated fatty acids. These results suggest that an acidic moiety and unsaturated fatty acids are important factors for the inhibitory effect of phospholipids on ORC binding to origin DNA, as is the case for DnaA. The inhibitory effect of cardiolipin on ORC binding to origin DNA was more apparent at 30 degrees C than at 4 degrees C. Furthermore, chlorpromazine restored the ORC-origin interaction in the presence of cardiolipin. Since the presence of unsaturated fatty acids, low incubation temperatures, and the addition of chlorpromazine all decrease membrane fluidity, these results suggest that membrane fluidity is important for the inhibitory effect of acidic phospholipids on ORC-binding to origin DNA, as is the case for DnaA.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
