BBS Faculty Member - Lee Zou

Lee Zou

Department of Pathology

Massachusetts General Hospital Cancer Center
Building 149, 13th Street
Charlestown, MA 02129
Tel: 617-724-9534
Fax: 617-726-7808

Maintenance of genomic integrity is essential for the survival of all organisms. In humans, loss of genomic integrity is closely linked to cancers and other genetic diseases. The genomes of cells are constantly challenged by DNA damage, DNA replication problems, and other forms of cellular stresses. In response to such stresses, cells activate a complex signaling pathway, termed the checkpoint, to orchestrate various cellular responses. The checkpoint-mediated regulation and coordination of processes such as cell cycle transitions, DNA replication, DNA repair, transcription, and apoptosis are crucial for the stability of the genome. Mutations impairing the functions of this signaling pathway associate with cancers and cancer predisposition syndromes (e.g. p53, Brca1, ATM, Chk2, and Nbs1). Furthermore, checkpoint is activated at the early stage of human tumorigensis, suggesting a role of checkpoint as an anti-cancer barrier against the genomic instability induced by oncogenic stresses.

The long-term goal of our research is to understand how checkpoint is activated by genomic instability and oncogenic stresses, and how it coordinates and integrates the network of cellular processes to preserve genomic stability. Currently, our research is focused on three fundamental questions about checkpoint signaling. First, how is checkpoint activated by DNA damage in cells? Second, how does checkpoint transmit DNA damage signals through different types of protein modifications? Third, how does checkpoint protect the DNA replication forks encountering DNA damage? To address these questions, we are developing new biochemical and cell biological assays to examine the functions of the key checkpoint proteins. The ATR-ATRIP kinase complex is a central player for the checkpoint responses in human cells. We recently found that single-stranded DNA (ssDNA) coated with RPA, a common structure generated at DNA damage and stalled replication forks, is the key structure that recruits ATR-ATRIP. Our biochemical analyses have enabled us to establish an in vitro assay recapitulating the initial steps of checkpoint activation. Using this system, we are systematically investigating how the checkpoint-signaling complex (so called the “checkosome”) is assembled on RPA-coated ssDNA and other DNA structures, and to identify novel proteins involved in checkpoint responses. We are also developing new assay systems to characterize stalled DNA replication forks in cells, and to visualize how replication and repair are coordinated. Furthermore, we are exploring new strategies to target cancer cells using specific checkpoint regulators as a weapon.

Last Update: 7/29/2015


For a complete listing of publications click here.



Buisson, R., Boisvert, J. L., Benes, C. H., and Zou, L. Distinct but Concerted Roles of ATR, DNA-PK and Chk1 in Countering Replication Stress during S Phase. Mol. Cell (Sept 10, 2015).

Flynn, R. L., Cox, K. E., Jeitany, M., Wakimoto, H., Bryll, A. R., Ganem, N. J., Bersani, F., Pineda, J. R., Suva, M., Benes, C. H., Haber, D. A., Boussin, F. D., and
Zou, L. (2015) Alternative Lengthening of Telomeres Renders Cancer Cells Hypersensitive ATR Inhibitors. Science 347:273-277.

Ouyang, J., Garner, E., Marechal, A., Hallet, A., Rickman, K. A., Gill, G., Smogorzewska, A., and
Zou, L. (2015) Non-covalent Interactions with SUMO and Ubiquitin Orchestrate Distinct Functions of the SLX4 Complex in Genome Maintenance. Mol. Cell 57:108-122.

Marechal, A., Li. J. M., Ji, J., Wu, C., Yazinski, S. A., Nguyen, H. D., Liu, S., Jimenez, A. E., Jin, J., and
Zou, L. (2014) PRP19 transforms into a sensor of RPA-ssDNA after DNA damage and drives ATR activation via a ubiquitin circuitry. Mol. Cell 53:235-246.

Flynn, R. L., Centore, C. R., O’Sullivan, R. J., Rai, R., Tse, A., Songyang, Z., Chang, S., Karlseder, J., and
Zou, L. (2011) TERRA and hnRNPA1 Orchestrate an RPA-to-POT1 Switch on Telomeric Single-Stranded DNA. Nature 471:532-536.

© 2015 by the President and Fellows of Harvard College