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APE1 a multifunctional enzyme that plays a central role in the cellular response to oxidative stress including DNA repair and redox regulation of transcriptional factors. Binds DNA and RNA. Functions as an apurinic/apyrimidinic (AP) endodeoxyribonuclease in the DNA base excision repair (BER) pathway, a 3'-5' exoribonuclease for mismatched deoxyribonucleotides at the 3' termini of nicked or gapped DNA molecules, and a DNA 3' phosphodiesterase capable of removing lesions (such as phosphoglycolate) blocking the 3' side of DNA strand breaks. Is a loading factor for POLB onto non-incised AP sites in DNA, stimulates the 5'-terminal deoxyribose 5'- phosphate (dRp) excision activity of POLB, and involved in the DNA cleavage step of class switch recombination (CSR). Possesses reversible nuclear redox activity to regulate DNA binding affinity and transcriptional activity of transcriptional factors by controlling the redox status of their DNA-binding domain, such as the FOS/JUN AP-1 complex after exposure to IR. Binds to negative calcium response elements (nCaREs). Stimulates the YBX1-mediated MDR1 promoter activity, when acetylated at Lys-6 and Lys-7, leading to drug resistance. Is an endoribonuclease involved in the control of single-stranded RNA metabolism. Plays a role in regulating MYC mRNA turnover. In association with NMD1, plays a role in the rRNA quality control process during cell cycle progression. Interacts with SIRT1; the interaction is increased in the context of genotoxic stress. Interacts with HDAC1, HDAC2 and HDAC3; the interactions are not dependent on the APEX1 acetylation status. Up-regulated in presence of reactive oxygen species (ROS), like bleomycin, H2O2 and phenazine methosulfate. NPM1 stimulates endodeoxyribonuclease activity on double-stranded DNA with AP sites, but inhibits endoribonuclease activity on single-stranded RNA containing AP sites. Belongs to the DNA repair enzymes AP/ExoA family. Note: This description may include information from UniProtKB.
Protein type: DNA repair, damage; DNA-binding; Deoxyribonuclease; EC; Endoplasmic reticulum; Hydrolase; Lyase; Nuclear receptor co-regulator; Nucleolus; Transcription, coactivator/corepressor
Chromosomal Location of Human Ortholog: 14q11.2
Cellular Component: centrosome; cytoplasm; endoplasmic reticulum; mitochondrion; nuclear chromosome, telomeric region; nuclear speck; nucleolus; nucleoplasm; nucleus; perinuclear region of cytoplasm; ribosome
Molecular Function: 3'-5' exonuclease activity; chromatin DNA binding; damaged DNA binding; DNA binding; DNA-(apurinic or apyrimidinic site) lyase activity; double-stranded DNA specific 3'-5' exodeoxyribonuclease activity; double-stranded DNA specific exodeoxyribonuclease activity; double-stranded telomeric DNA binding; endodeoxyribonuclease activity; endonuclease activity; metal ion binding; oxidoreductase activity; phosphodiesterase I activity; phosphoric diester hydrolase activity; protein binding; ribonuclease H activity; RNA binding; site-specific endodeoxyribonuclease activity, specific for altered base; transcription coactivator activity; transcription corepressor activity; uracil DNA N-glycosylase activity
Biological Process: base-excision repair; base-excision repair, base-free sugar-phosphate removal; DNA repair; positive regulation of DNA repair; regulation of apoptosis; regulation of mRNA stability; telomere maintenance
Reference #:  P27695 (UniProtKB)
Alt. Names/Synonyms: AP endonuclease 1; AP endonuclease class I; AP lyase; APE; APE1; APEN; APEX; APEX nuclease; APEX nuclease (multifunctional DNA repair enzyme) 1; APEX1; Apurinic-apyrimidinic endonuclease 1; apurinic/apyrimidinic (abasic) endonuclease; apurinic/apyrimidinic exonuclease; APX; deoxyribonuclease (apurinic or apyrimidinic); DNA-(apurinic or apyrimidinic site) lyase; HAP1; multifunctional DNA repair enzyme; Protein REF-1; redox factor 1; REF1
Gene Symbols: APEX1
Molecular weight: 35,555 Da
Basal Isoelectric point: 8.33  Predict pI for various phosphorylation states
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