title: A gemcitabine sensitivity screen identifies a role for NEK9 in the replication stress response.
abstract: The Replication Stress Response (RSR) is a signaling network that recognizes challenges to DNA replication and coordinates diverse DNA repair and cell-cycle checkpoint pathways. Gemcitabine is a nucleoside analogue that causes cytotoxicity by inducing DNA replication blocks. Using a synthetic lethal screen of a RNAi library of nuclear enzymes to identify genes that when silenced cause gemcitabine sensitization or resistance in human triple-negative breast cancer cells, we identified NIMA (never in mitosis gene A)-related kinase 9 (NEK9) as a key component of the RSR. NEK9 depletion in cells leads to replication stress hypersensitivity, spontaneous accumulation of DNA damage and RPA70 foci, and an impairment in recovery from replication arrest. NEK9 protein levels also increase in response to replication stress. NEK9 complexes with CHK1, and moreover, NEK9 depletion impairs CHK1 autophosphorylation and kinase activity in response to replication stress. Thus, NEK9 is a critical component of the RSR that promotes CHK1 activity, maintaining genome integrity following challenges to DNA replication.
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Smith
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Aleksandra V
authors.initials: AV
authors.lastname: Petrova
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Matthew Z
authors.initials: MZ
authors.lastname: Madden
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Warren
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Claire W
authors.initials: CW
authors.lastname: Hardy
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Liang
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Elaine A
authors.initials: EA
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: M Hope
authors.initials: MH
authors.lastname: Robinson
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Soumon
authors.initials: S
authors.lastname: Rudra
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Ehdaivand
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Mylin A
authors.initials: MA
authors.lastname: Torres
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA dsyu@emory.edu.
authors.forename: David S
authors.initials: DS
authors.lastname: Yu
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D004249:DNA Damage; D004261:DNA Replication; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D006801:Humans; D000072379:NIMA-Related Kinases; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051716:Replication Protein A / Q000032:analysis; D013312:Stress, Physiological / Q000235:genetics*; D064726:Triple Negative Breast Neoplasms / Q000235:genetics; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; C497167:RPA1 protein, human; D051716:Replication Protein A; D003841:Deoxycytidine; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; C462119:NEK9 protein, human; D000072379:NIMA-Related Kinases; D017346:Protein Serine-Threonine Kinases; D000093542:Gemcitabine