Effect of multifunctional protein YB-1 on the AP site cleavage by AP endonuclease 1 and tyrosyl phosphodiesterase 1

Poly(ADP-ribose)polymerase 1 stimulates the AP-site cleavage activity of tyrosyl-DNA phosphodiesterase 1

APE-independent base excision repair (BER) pathway plays an important role in the regulation of DNA repair mechanisms. In this study it has been found that recently discovered tyrosyl-DNA phosphodiesterase 1 (Tdp1) catalyzes the AP site cleavage reaction to generate breaks with the 3'- and 5'-phosphate termini. The removal of the 3'-phosphate is performed by polynucleotide kinase phosphatase (P...

Pre-steady-state kinetic characterization of the AP endonuclease activity of human AP endonuclease 1.

Human AP endonuclease 1 (APE1, REF1) functions within the base excision repair pathway by catalyzing the hydrolysis of the phosphodiester bond 5 ' to a baseless sugar (apurinic or apyrimidinic site). The AP endonuclease activity of this enzyme and two active site mutants were characterized using equilibrium binding and pre-steady-state kinetic techniques. Wild-type APE1 is a remarkably potent e...

Human AP-endonuclease 1 and hnRNP-L interact with a nCaRE-like repressor element in the AP-endonuclease 1 promoter.

The major human AP-endonuclease 1 (APE1) is a multifunctional protein that plays a central role in the repair of damaged DNA by acting as a dual-function nuclease in the base excision repair pathway. This enzyme was also independently identified as a redox activator of AP-1 DNA-binding activity and has subsequently been shown to activate a variety of transcription factors via a redox mechanism....

Effects of DNA and protein size on substrate cleavage by human tyrosyl-DNA phosphodiesterase 1.

TDP (tyrosyl-DNA phosphodiesterase) 1 catalyses the hydrolysis of phosphodiester linkages between a DNA 3' phosphate and a tyrosine residue as well as a variety of other DNA 3' substituents, and has been implicated in the repair of covalent complexes involving eukaryotic type IB topoisomerases. To better understand the substrate features that are recognized by TDP1, the size of either the DNA o...

Potent Inhibition of Human Ap Endonuclease 1 by Arylstibonic Acids