6fcm
Crystal structure of human PCNA
Structural highlights
FunctionPCNA_HUMAN Auxiliary protein of DNA polymerase delta and is involved in the control of eukaryotic DNA replication by increasing the polymerase's processibility during elongation of the leading strand. Induces a robust stimulatory effect on the 3'-5' exonuclease and 3'-phosphodiesterase, but not apurinic-apyrimidinic (AP) endonuclease, APEX2 activities. Has to be loaded onto DNA in order to be able to stimulate APEX2. Plays a key role in DNA damage response (DDR) by being conveniently positioned at the replication fork to coordinate DNA replication with DNA repair and DNA damage tolerance pathways. Acts as a loading platform to recruit DDR proteins that allow completion of DNA replication after DNA damage and promote postreplication repair: Monoubiquitinated PCNA leads to recruitment of translesion (TLS) polymerases, while 'Lys-63'-linked polyubiquitination of PCNA is involved in error-free pathway and employs recombination mechanisms to synthesize across the lesion.[1] [2] Publication Abstract from PubMedNeutrophils produce high levels of reactive oxygen species (ROS) by NADPH oxidase that are crucial for host defense but can lead to tissue injury when produced in excess. We previously described that proliferating cell nuclear antigen (PCNA), a nuclear scaffolding protein pivotal in DNA synthesis, controls neutrophil survival through its cytosolic association with procaspases. We herein showed that PCNA associated with p47phox, a key subunit of NADPH oxidase, and that this association regulated ROS production. Surface plasmon resonance and crystallography techniques demonstrated that the interdomain-connecting loop of PCNA interacted directly with the phox homology (PX) domain of the p47phox. PCNA inhibition by competing peptides or by T2AA, a small-molecule PCNA inhibitor, decreased NADPH oxidase activation in vitro. Furthermore, T2AA provided a therapeutic benefit in mice during trinitro-benzene-sulfonic acid (TNBS)-induced colitis by decreasing oxidative stress, accelerating mucosal repair, and promoting the resolution of inflammation. Our data suggest that targeting PCNA in inflammatory neutrophils holds promise as a multifaceted antiinflammatory strategy. Cytosolic PCNA interacts with p47phox and controls NADPH oxidase NOX2 activation in neutrophils.,Ohayon D, De Chiara A, Dang PM, Thieblemont N, Chatfield S, Marzaioli V, Burgener SS, Mocek J, Candalh C, Pintard C, Tacnet-Delorme P, Renault G, Lagoutte I, Favier M, Walker F, Hurtado-Nedelec M, Desplancq D, Weiss E, Benarafa C, Housset D, Marie JC, Frachet P, El-Benna J, Witko-Sarsat V J Exp Med. 2019 Nov 4;216(11):2669-2687. doi: 10.1084/jem.20180371. Epub 2019 Sep, 6. PMID:31492810[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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