• Login
    View Item 
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UMB Digital ArchiveCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    The DNA synthesome: A discrete multiprotein complex and a model for studying anticancer drug action

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Find Full text
    Author
    Jiang, HaiYan
    Advisor
    Malkas, Linda H.
    Date
    1999
    Type
    dissertation
    
    Metadata
    Show full item record
    Abstract
    The concept that many enzymes and factors involved in mammalian DNA replication function together as an organized multiprotein complex has been supported by an ever-increasing body of evidence. In this study, a discrete high molecular weight multiprotein complex containing DNA polymerase alpha was identified by a native Western blotting technique. An enrichment of this complex was seen at each step in its purification. The integrity of this complex was maintained after ion-exchange chromatography and sucrose gradients sedimentation. We have designated this complex the DNA synthesome. The DNA synthesome was further purified by electroeluting this complex from a native polyacrylamide gel. We have verified that the electroeluted synthesome is capable to support all aspects of DNA replication in vitro. Furthermore, SDS-PAGE analysis of the electroeluted DNA synthesome revealed the presence of at least 25 major polypeptides with molecular weights ranging from 20 kD to 240 kD. In addition, using Western blot and enzymatic analysis, we have shown that this complex contains replication essential proteins DNA polymerase delta, proliferating cell nuclear antigen (PCNA), replication protein A (RP-A), and topoisomerases I and II. Taken together, our evidence suggests that the DNA synthesome represents the fundamental DNA replication unit the human cell. We also validated the use of the synthesome as an in vitro model for studying mechanism of action of anticancer drugs that directly affect cellular DNA synthesis. The effects of gemcitabine (dFdC) and araC on in vitro SV40 DNA synthesis mediated by the DNA synthesome was compared with that of on intact cell DNA synthesis. Our results showed that dFdC is a more potent inhibitor of intact cell DNA synthesis and in vitro SV40 DNA replication than araC. Although dFdCTP is more potent than araCTP at inhibiting in vitro SV40 DNA synthesis, there is no significant difference between the inhibitory effect of these two drugs on the activity of the MCF7 synthesome associated DNA polymerases alpha and delta. Our results also suggested that the decrease in the synthesome mediated in vitro SV40 DNA synthesis by dFdCTP and araCTP is primarily through inhibition of the synthesome associated DNA polymerase alpha activity.
    Description
    University of Maryland, Baltimore. Pharmacology and Experimental Therapeutics. Ph.D. 1999
    Keyword
    Biology, Molecular
    Biology, Cell
    Health Sciences, Pharmacology
    DNA synthesome
    DNA Polymerase I
    Multiprotein Complexes
    Identifier to cite or link to this item
    http://hdl.handle.net/10713/1310
    Collections
    Theses and Dissertations All Schools
    Theses and Dissertations School of Medicine

    entitlement

     
    DSpace software (copyright © 2002 - 2022)  DuraSpace
    Quick Guide | Policies | Contact Us | UMB Health Sciences & Human Services Library
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.