UNLABELLED Low-to-moderate levels of reactive oxygen species (ROS) govern different steps of neurogenesis via molecular pathways that have been decrypted only partially. Although it has been postulated that redox-sensitive molecules are involved in neuronal differentiation, the molecular bases for this process have not been elucidated yet. The aim of this work was therefore to study the role pl...

Repair of apurinic/apyrimidinic (AP) sites is initiated by AP endonucleases, such as the human Ape1 protein (also called Hap1, Apex, and Ref1). This and related enzymes show strong dependence on divalent cations, particularly magnesium. Here we explore the role of this metal in different stages of the Ape1 reaction: substrate binding, cleavage, and product release. We examined DNA binding using...

Base Excision Repair (BER) efficiently corrects the most common types of DNA damage in mammalian cells. Step-by-step coordination of BER is facilitated by multiple interactions between enzymes and accessory proteins involved. Here we characterize quantitatively a number of complexes formed by DNA polymerase β (Polβ), apurinic/apyrimidinic endonuclease 1 (APE1), poly(ADP-ribose) polymerase 1 (PA...

The main goal of this work is to investigate the killing effects and molecular mechanism of photodynamic therapy (PDT) mediated by the Ad5/F35-APE1 siRNA recombinant adenovirus in combination with a hematoporphrphyrin derivative (HpD) in the A549 human lung adenocarcinoma cell line in vitro to provide a theoretical reference for treating lung cancer by HpD-PDT. By using the technologies of MTT,...

Dually targeted mitochondrial proteins usually possess an unconventional mitochondrial targeting sequence (MTS), which makes them difficult to predict by current bioinformatics approaches. Human apurinic/apyrimidinic endonuclease (APE1) plays a central role in the cellular response to oxidative stress. It is a dually targeted protein preferentially residing in the nucleus with conditional distr...

The endonucleolytic activity of human apurinic/apyrimidinic endonuclease (AP endo, Ape1) is a major factor in the maintenance of the integrity of the genome. On the other side, as an undesired effect, Ape1 overexpression has been linked to resistance to radioand chemo-therapy treatments in several human tumors. Inhibition of Ape1 using siRNA or the expression of a dominant-negative form of the ...

APE1/Ref-1 is thought to be a multifunctional protein involved in reduction-oxidation (redox) regulation and base excision DNA repair, and is required for early embryonic development in mice. APE1/Ref-1 has redox activity and AP endonuclease activity, and is able to enhance DNA-binding activity of several transcription factors, including NF-kappaB, AP-1 and p53, through reduction of their criti...

Ape1 is an important redox protein, essential for specific cytokine-induced signal transduction. Ape1 signaling is also important in regulating the growth of cancer cells, including colon cancer cells. The present study investigated whether Ape1 signaling plays a role in the regulation of colon cancer stem cell (CCSC) growth. The results showed that Ape1 was aberrantly expressed in CCSCs, as de...

Apurinic/apyrimidinic endonuclease 1 (APE1) is the predominant AP site repair enzyme in mammals. APE1 also maintains 3'-5' exonuclease and 3'-repair activities, and regulates transcription factor DNA binding through its REF-1 function. Since complete or severe APE1 deficiency leads to embryonic lethality and cell death, it has been hypothesized that APE1 protein variants with slightly impaired ...

PURPOSE Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that shows elevated expression in a number of cancers. We attempted to determine whether serum APE1/Ref-1 is elevated in patients with bladder cancer. MATERIALS AND METHODS Serum APE1/Ref-1 levels were determined using enzyme-linked immunosorbent assay in serum from patients with bladder canc...