RECQ5-dependent SUMOylation of DNA topoisomerase I prevents transcription-associated genome instability.

Nature communications (2015-04-09)
Min Li, Subhash Pokharel, Jiin-Tarng Wang, Xiaohua Xu, Yilun Liu
RESUMEN

DNA topoisomerase I (TOP1) has an important role in maintaining DNA topology by relaxing supercoiled DNA. Here we show that the K391 and K436 residues of TOP1 are SUMOylated by the PIAS1-SRSF1 E3 ligase complex in the chromatin fraction containing active RNA polymerase II (RNAPIIo). This modification is necessary for the binding of TOP1 to RNAPIIo and for the recruitment of RNA splicing factors to the actively transcribed chromatin, thereby reducing the formation of R-loops that lead to genome instability. RECQ5 helicase promotes TOP1 SUMOylation by facilitating the interaction between PIAS1, SRSF1 and TOP1. Unexpectedly, the topoisomerase activity is compromised by K391/K436 SUMOylation, and this provides the first in vivo evidence that TOP1 activity is negatively regulated at transcriptionally active chromatin to prevent TOP1-induced DNA damage. Therefore, our data provide mechanistic insight into how TOP1 SUMOylation contributes to genome maintenance during transcription.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Glycerol, for molecular biology, ≥99.0%
Sigma-Aldrich
HEPES, ≥99.5% (titration)
Sigma-Aldrich
L-Glutathione reduced, ≥98.0%
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)
Sigma-Aldrich
HEPES, BioPerformance Certified, ≥99.5% (titration), suitable for cell culture
Sigma-Aldrich
Glycerol, ≥99.5%
Sigma-Aldrich
Magnesium chloride, anhydrous, ≥98%
Sigma-Aldrich
Magnesium chloride solution, for molecular biology, 1.00 M±0.01 M
Sigma-Aldrich
Sodium chloride, for molecular biology, DNase, RNase, and protease, none detected, ≥99% (titration)
Sigma-Aldrich
Ethylenediaminetetraacetic acid, ACS reagent, 99.4-100.6%, powder
Sigma-Aldrich
DL-Dithiothreitol solution, BioUltra, for molecular biology, ~1 M in H2O
Sigma-Aldrich
Sodium chloride, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99%
Sigma-Aldrich
Sodium chloride solution, 0.9% in water, BioXtra, suitable for cell culture
Sigma-Aldrich
Sodium chloride solution, 5 M in H2O, BioReagent, for molecular biology, suitable for cell culture
Sigma-Aldrich
Ethylenediaminetetraacetic acid, anhydrous, BioUltra, ≥99% (titration)
Supelco
DL-Dithiothreitol solution, 1 M in H2O
Millipore
ANTI-FLAG® antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution
Sigma-Aldrich
HEPES buffer solution, 1 M in H2O
Sigma-Aldrich
Glycerol, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for electrophoresis, ≥99% (GC)
Sigma-Aldrich
Sodium chloride solution, 5 M
SAFC
Sodium chloride solution, 5 M
Sigma-Aldrich
L-Glutathione reduced, suitable for cell culture, BioReagent, ≥98.0%, powder
Sigma-Aldrich
Ethylenediaminetetraacetic acid, anhydrous, crystalline, BioReagent, suitable for cell culture
Sigma-Aldrich
Ethylenediaminetetraacetic acid solution, 0.02% in DPBS (0.5 mM), sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Sodium chloride, meets analytical specification of Ph. Eur., BP, USP, 99.0-100.5%
SAFC
HEPES
Sigma-Aldrich
Ethylenediaminetetraacetic acid, purified grade, ≥98.5%, powder
Sigma-Aldrich
Glycerin, meets USP testing specifications
Sigma-Aldrich
Magnesium chloride, powder, <200 μm
Sigma-Aldrich
Magnesium chloride solution, BioUltra, for molecular biology, ~1 M in H2O