Mechanism of auto-inhibition and activation of Mec1ATR checkpoint kinase
| Autor: | Xiaodong Zhang, Elias Tannous, Peter M. J. Burgers, Luke A. Yates |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
MEC1/ATR
Cell Cycle Proteins Ataxia Telangiectasia Mutated Proteins DNA damage response 0302 clinical medicine Structural Biology ATRIP enzyme kinetics Chromosome instability CRYO-EM STRUCTURE checkpoint control cryoEM structures 11 Medical and Health Sciences 0303 health sciences Kinase Chemistry Intracellular Signaling Peptides and Proteins activation mechanism serine/threonine protein kinase Cell biology Regulatory sequence 03 Chemical Sciences Life Sciences & Biomedicine Programmed cell death Biochemistry & Molecular Biology Saccharomyces cerevisiae Proteins DNA repair DNA damage Biophysics Saccharomyces cerevisiae Protein Serine-Threonine Kinases Article 03 medical and health sciences Homologous chromosome Humans Molecular Biology 030304 developmental biology Science & Technology BAYESIAN-APPROACH Wild type Cell Biology PROTEIN-KINASE 06 Biological Sciences DNA-DAMAGE ATM BEAM-INDUCED MOTION HISTONE H2A 030217 neurology & neurosurgery REPLICATION CHECKPOINT DNA Damage Developmental Biology |
| Zdroj: | Nature structural & molecular biology |
| Popis: | In response to DNA damage or replication fork stalling, the basal activity of Mec1ATR is stimulated in a cell-cycle-dependent manner, leading to cell-cycle arrest and the promotion of DNA repair. Mec1ATR dysfunction leads to cell death in yeast and causes chromosome instability and embryonic lethality in mammals. Thus, ATR is a major target for cancer therapies in homologous recombination–deficient cancers. Here we identify a single mutation in Mec1, conserved in ATR, that results in constitutive activity. Using cryo-electron microscopy, we determine the structures of this constitutively active form (Mec1(F2244L)-Ddc2) at 2.8 A and the wild type at 3.8 A, both in complex with Mg2+-AMP-PNP. These structures yield a near-complete atomic model for Mec1–Ddc2 and uncover the molecular basis for low basal activity and the conformational changes required for activation. Combined with biochemical and genetic data, we discover key regulatory regions and propose a Mec1 activation mechanism. Cryo-EM structures and functional analyses of wild-type and constitutively active Mec1–Ddc2 complexes reveal the basis of Mec1 kinase activation and how Dpb11 stimulates Mec1 activity. |
| Databáze: | OpenAIRE |
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