A 39 amino acid fragment of the cell cycle regulator p21 is sufficient to bind PCNA and partially inhibit DNA replication in vivo

Junjie Chen, Richard Peters, Partha Saha, Patrick Lee, Annie Theodoras, Michele Pagano, Gerhard Wagner, Anindya Dutta

Research output: Contribution to journalArticlepeer-review

75 Citations (Scopus)

Abstract

The cell cycle regulator p21 interacts with and inhibits the DNA replication and repair factor proliferating cell nuclear antigen (PCNA). We have defined a 39 amino acid fragment of p21 which is sufficient to bind PCNA with high affinity (K(d) 10-20 nM). This peptide can inhibit DNA replication in vitro and microinjection of a GST fusion protein containing this domain inhibited S phase in vivo. Despite its high affinity for PCNA, the free 39 amino acid peptide does not have a well-defined structure, as judged from circular dichroism and nuclear magnetic resonance measurements, suggesting an induced fit mechanism for the PCNA-p21 interaction. The association of the small peptide with PCNA was thermolabile, suggesting that portions of p21 adjoining the minimal region of contact stabilize the interaction. In addition, a domain containing 67 amino acids from the N-terminus of PCNA was defined as both necessary and sufficient for binding to p21.

Original languageEnglish
Pages (from-to)1727-1733
Number of pages7
JournalNucleic Acids Research
Volume24
Issue number9
DOIs
Publication statusPublished - 1996
Externally publishedYes

Bibliographical note

Funding Information:
We thank members of the Dutta Laboratory and G.Lindenmeyer and D.Gilbert for helpful discussions, J.Morrow for technical assistance, J.Parvin for reading the manuscript, C.Dahl for help with peptide synthesis and J.Lee for use of the CD spectrometer. This work was supported by a grant from the NIH (CA60499) and career development awards from the American Cancer Society (JFRA 474) and the US Armed Forces Medical Research Command (DAMD17-94-J-4064). JC was supported by a post-doctoral fellowship (DAMD 17-94-J-4070), RP is a Howard Hughes Medical Institute Physician Post-doctoral Fellow, and MP was supported in part by HSFP grant RG-496/93.

ASJC Scopus Subject Areas

  • Genetics

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

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