A novel mechanism for regulating the activity of proliferating cell nuclear antigen by a small protein.

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TitleA novel mechanism for regulating the activity of proliferating cell nuclear antigen by a small protein.
Publication TypeJournal Article
Year of Publication2014
AuthorsLi, Z, Huang, RY-C, Yopp, DC, Hileman, TH, Santangelo, TJ, Hurwitz, J, Hudgens, JW, Kelman, Z
JournalNucleic Acids Res
Date Published2014 May
KeywordsAmino Acid Substitution, Archaeal Proteins, Deuterium Exchange Measurement, DNA Polymerase II, Flap Endonucleases, Kinetics, Microbial Viability, Models, Molecular, Mutagenesis, Site-Directed, Proliferating Cell Nuclear Antigen, Protein Binding, Protein Interaction Domains and Motifs, Protein Multimerization, Thermococcus

Proliferating cell nuclear antigen (PCNA) forms a trimeric ring that associates with and influences the activity of many proteins participating in DNA metabolic processes and cell cycle progression. Previously, an uncharacterized small protein, encoded by TK0808 in the archaeon Thermococcus kodakarensis, was shown to stably interact with PCNA in vivo. Here, we show that this protein, designated Thermococcales inhibitor of PCNA (TIP), binds to PCNA in vitro and inhibits PCNA-dependent activities likely by preventing PCNA trimerization. Using hydrogen/deuterium exchange mass spectrometry and site-directed mutagenesis, the interacting regions of PCNA and TIP were identified. Most proteins bind to PCNA via a PCNA-interacting peptide (PIP) motif that interacts with the inter domain connecting loop (IDCL) on PCNA. TIP, however, lacks any known PCNA-interacting motif, suggesting a new mechanism for PCNA binding and regulation of PCNA-dependent activities, which may support the development of a new subclass of therapeutic biomolecules for inhibiting PCNA.

Alternate JournalNucleic Acids Res.
PubMed ID24728986
PubMed Central IDPMC4027161
Grant ListGH034559 / GH / CGH CDC HHS / United States
GM098176 / GM / NIGMS NIH HHS / United States
GM100329 / GM / NIGMS NIH HHS / United States
R01 GM100329 / GM / NIGMS NIH HHS / United States
/ / Intramural NIH HHS / United States