Skip to main content
Advertisement

Main menu

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET

User menu

  • My alerts
  • Log in
  • My Cart

Search

  • Advanced search
Molecular Pharmacology
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET
  • My alerts
  • Log in
  • My Cart
Molecular Pharmacology

Advanced Search

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Visit molpharm on Facebook
  • Follow molpharm on Twitter
  • Follow molpharm on LinkedIn
Research ArticleArticle

Domain Interactions Affecting Human DNA Topoisomerase I Catalysis and Camptothecin Sensitivity

Paola Fiorani, James F. Amatruda, Alessandra Silvestri, Richard H. Butler, Mary-Ann Bjornsti and Piero Benedetti
Molecular Pharmacology December 1999, 56 (6) 1105-1115; DOI: https://doi.org/10.1124/mol.56.6.1105
Paola Fiorani
1 2
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
James F. Amatruda
1 2
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Alessandra Silvestri
1 2
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Richard H. Butler
1 2
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Mary-Ann Bjornsti
1 2
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Piero Benedetti
1 2
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Figures & Data
  • Info & Metrics
  • eLetters
  • PDF
Loading

Abstract

DNA topoisomerase I (Top1p) relaxes supercoiled DNA by the formation of a covalent intermediate in which the active site tyrosine is transiently bound to the severed DNA strand. The antineoplastic agent camptothecin (Cpt) specifically targets Top1p and several mutations have been isolated that render the enzyme Cpt resistant. The mutated residues, although located in different regions of the enzyme, may constitute part of the Cpt binding site. To begin identifying the structural features of DNA Top1p important for Cpt-induced cytotoxicity, we developed a novel yeast genetic screen to isolate catalytically active, yet Cpt-resistant enzymes from a pool of humantop1 mutants. Among the mutations isolated were substitutions of Ser or Val for Gly363, which like the Gly363 to Cys mutation previously reported by us, suppressed the Cpt sensitivity of Top1p. In contrast, each amino-acid substitution differed in its ability to suppress the lethal phenotype and catalytic activity of a human top1 mutant top1T718A that resembles Cpt by stabilizing the covalent intermediate. Biochemical analyses and molecular modeling support a model where interactions between two conserved domains, a central “lip” region containing residue Gly363 and the residues around the active site tyrosine (Tyr723), directly affect the formation of the Cpt-binding site and enzyme catalysis.

Footnotes

    • Received November 16, 1998.
    • Accepted August 13, 1999.
  • Send reprint requests to: Dr. Piero Benedetti, Istituto di Biologia Cellulare, “Campus Adriano Buzzati-Traverso” Consiglio Nazionale delle Ricerche, via Ramarini 32, Monterotonda 00016, Rome, Italy. E-mail: pbenedetti{at}ibc.rm.cnr.it

  • ↵1 Current Address: Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105.

  • ↵2 Current Address: Division of Medical Oncology, Dana-Farber Cancer Institute, 44 Binney St., Boston, MA 02115.

  • This work was supported by a grant from Associazione Italiana per la Ricerca sul Cancro (to P.B.) and by National Institutes of Health Grant CA70406 (to M.-A.B.). P.F and A.S. were supported by fellowships from Fondazione A. Buzzati-Traverso and J.F.A. by a Yamagiwa-Yoshida fellowship from International Union Against Cancer.

  • The American Society for Pharmacology and Experimental Therapeutics
View Full Text

MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years. 

Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page. 

 

  • Click here for information on institutional subscriptions.
  • Click here for information on individual ASPET membership.

 

Log in using your username and password

Forgot your user name or password?

Purchase access

You may purchase access to this article. This will require you to create an account if you don't already have one.
PreviousNext
Back to top

In this issue

Molecular Pharmacology: 56 (6)
Molecular Pharmacology
Vol. 56, Issue 6
1 Dec 1999
  • Table of Contents
  • About the Cover
  • Index by author
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for sharing this Molecular Pharmacology article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Domain Interactions Affecting Human DNA Topoisomerase I Catalysis and Camptothecin Sensitivity
(Your Name) has forwarded a page to you from Molecular Pharmacology
(Your Name) thought you would be interested in this article in Molecular Pharmacology.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Research ArticleArticle

Domain Interactions Affecting Human DNA Topoisomerase I Catalysis and Camptothecin Sensitivity

Paola Fiorani, James F. Amatruda, Alessandra Silvestri, Richard H. Butler, Mary-Ann Bjornsti and Piero Benedetti
Molecular Pharmacology December 1, 1999, 56 (6) 1105-1115; DOI: https://doi.org/10.1124/mol.56.6.1105

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero

Share
Research ArticleArticle

Domain Interactions Affecting Human DNA Topoisomerase I Catalysis and Camptothecin Sensitivity

Paola Fiorani, James F. Amatruda, Alessandra Silvestri, Richard H. Butler, Mary-Ann Bjornsti and Piero Benedetti
Molecular Pharmacology December 1, 1999, 56 (6) 1105-1115; DOI: https://doi.org/10.1124/mol.56.6.1105
del.icio.us logo Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Jump to section

  • Article
    • Abstract
    • Experimental Procedures
    • Results
    • Discussion
    • Acknowledgments
    • Footnotes
    • Abbreviations
    • References
  • Figures & Data
  • Info & Metrics
  • eLetters
  • PDF

Related Articles

Cited By...

More in this TOC Section

  • Human mAb 3F1 targeting the fuctional epitopes of Siglec-15
  • The regulation and mechanisms of ImKTX58 on KV1.3 channel
  • EIPA, HMA and SMN2 gene regulation
Show more Article

Similar Articles

Advertisement
  • Home
  • Alerts
Facebook   Twitter   LinkedIn   RSS

Navigate

  • Current Issue
  • Fast Forward by date
  • Fast Forward by section
  • Latest Articles
  • Archive
  • Search for Articles
  • Feedback
  • ASPET

More Information

  • About Molecular Pharmacology
  • Editorial Board
  • Instructions to Authors
  • Submit a Manuscript
  • Customized Alerts
  • RSS Feeds
  • Subscriptions
  • Permissions
  • Terms & Conditions of Use

ASPET's Other Journals

  • Drug Metabolism and Disposition
  • Journal of Pharmacology and Experimental Therapeutics
  • Pharmacological Reviews
  • Pharmacology Research & Perspectives
ISSN 1521-0111 (Online)

Copyright © 2022 by the American Society for Pharmacology and Experimental Therapeutics