title: Methods for studying checkpoint kinases - Chk1.
abstract: Attempts to passage through mitosis with unrepaired DNA damage or incompletely replicated DNA leads to genome instability and/or cell death. To prevent this from occurring, an ancient checkpoint (known as the G2 DNA damage checkpoint) that inhibits the activation of the mitotic cyclin-dependent kinase is activated to hold cells in the G2 phase of the cell cycle. The effector of this checkpoint is Chk1, a protein serine-threonine kinase. Chk1 contains an N-terminal catalytic domain, and C-terminal regulatory domain. Within the regulatory domain there are two residues, Serine-317 (S317) and Serine-345 (S345), which are phosphorylated in active Chk1 molecules, and subsequently dephosphorylated to inactivate Chk1 and allow mitotic entry. Phospho-specific antibodies can be used to detect these activating phosphorylations, and this provides a simple and sensitive marker of Chk1 activation.
authors.affiliation: Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA. claudia.tapia-alveal@mssm.edu
authors.forename: Claudia
authors.initials: C
authors.lastname: Tapia-Alveal
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: O'Connell
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D000071877:Checkpoint Kinase 1; D004249:DNA Damage / Q000235:genetics / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D051379:Mice; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; C000605869:Chek1 protein, mouse