TY - JOUR
T1 - The Checkpoint Clamp Activates Mec1 Kinase during Initiation of the DNA Damage Checkpoint
AU - Majka, Jerzy
AU - Niedziela-Majka, Anita
AU - Burgers, Peter M M.J.
N1 - Funding Information:
We thank Sara Binz and Marc Wold for a sample of RPA with the mutant Rpa2-9A, Noel Lowndes for strains, Timothy M. Lohman for help with the analytical centrifugation analysis, John Majors for critical discussions during the course of this work, and Carrie Stith for expert technical assistance. This work was supported in part by National Institutes of Health grants GM45948 (to Timothy M. Lohman) and GM32431 (to P.M.J.B.).
PY - 2006/12/28
Y1 - 2006/12/28
N2 - Yeast Mec1/Ddc2 protein kinase, the ortholog of human ATR/ATRIP, plays a central role in the DNA damage checkpoint. The PCNA-like clamp Rad17/Mec3/Ddc1 (the 9-1-1 complex in human) and its loader Rad24-RFC are also essential components of this signal transduction pathway. Here we have studied the role of the clamp in regulating Mec1, and we delineate how the signal generated by DNA lesions is transduced to the Rad53 effector kinase. The checkpoint clamp greatly activates the kinase activity of Mec1, but only if the clamp is appropriately loaded upon partial duplex DNA. Activated Mec1 phosphorylates the Ddc1 and Mec3 subunits of the clamp, the Rad24 subunit of the loader, and the Rpa1 and Rpa2 subunits of RPA. Phosphorylation of Rad53, and of human PHAS-1, a nonspecific target, also requires a properly loaded clamp. Phosphorylation and binding studies with individual clamp subunits indicate that the Ddc1 subunit mediates the functional interactions with Mec1.
AB - Yeast Mec1/Ddc2 protein kinase, the ortholog of human ATR/ATRIP, plays a central role in the DNA damage checkpoint. The PCNA-like clamp Rad17/Mec3/Ddc1 (the 9-1-1 complex in human) and its loader Rad24-RFC are also essential components of this signal transduction pathway. Here we have studied the role of the clamp in regulating Mec1, and we delineate how the signal generated by DNA lesions is transduced to the Rad53 effector kinase. The checkpoint clamp greatly activates the kinase activity of Mec1, but only if the clamp is appropriately loaded upon partial duplex DNA. Activated Mec1 phosphorylates the Ddc1 and Mec3 subunits of the clamp, the Rad24 subunit of the loader, and the Rpa1 and Rpa2 subunits of RPA. Phosphorylation of Rad53, and of human PHAS-1, a nonspecific target, also requires a properly loaded clamp. Phosphorylation and binding studies with individual clamp subunits indicate that the Ddc1 subunit mediates the functional interactions with Mec1.
KW - DNA
UR - https://www.scopus.com/pages/publications/33845607102
U2 - 10.1016/j.molcel.2006.11.027
DO - 10.1016/j.molcel.2006.11.027
M3 - Article
C2 - 17189191
AN - SCOPUS:33845607102
SN - 1097-2765
VL - 24
SP - 891
EP - 901
JO - Molecular cell
JF - Molecular cell
IS - 6
ER -