Dynamics of endogenous PARP1 and PARP2 during DNA damage revealed by live-cell single-molecule imaging

Jyothi Mahadevan; Asmita Jha; Johannes Rudolph; Samuel Bowerman; Domenic Narducci; Anders S Hansen; Karolin Luger

doi:10.1016/j.isci.2022.105779

Dynamics of endogenous PARP1 and PARP2 during DNA damage revealed by live-cell single-molecule imaging

iScience. 2022 Dec 9;26(1):105779. doi: 10.1016/j.isci.2022.105779. eCollection 2023 Jan 20.

Authors

Jyothi Mahadevan¹, Asmita Jha², Johannes Rudolph¹, Samuel Bowerman^{1

3}, Domenic Narducci², Anders S Hansen², Karolin Luger^{1

3}

Affiliations

¹ Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA.
² Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
³ Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80309, USA.

Abstract

PARP1 contributes to genome architecture and DNA damage repair through its dynamic association with chromatin. PARP1 and PARP2 (PARP1/2) recognize damaged DNA and recruit the DNA repair machinery. Using single-molecule microscopy in live cells, we monitored the movement of PARP1/2 on undamaged and damaged chromatin. We identify two classes of freely diffusing PARP1/2 and two classes of bound PARP1/2. The majority (>60%) of PARP1/2 diffuse freely in both undamaged and damaged nuclei and in the presence of inhibitors of PARP1/2 used for cancer therapy (PARPi). Laser-induced DNA damage results in a small fraction of slowly diffusing PARP1 and PARP2 to become transiently bound. Treatment of cells with PARPi in the presence of DNA damage causes subtle changes in the dynamics of bound PARP1/2, but not the high levels of PARP1/2 trapping seen previously. Our results imply that next-generation PARPi could specifically target the small fraction of DNA-bound PARP1/2.

Keywords: Biological sciences; Cell biology; Molecular biology; Organizational aspects of cell biology.

Abstract

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