The fission yeast DNA structure checkpoint protein Rad26ATRIP/LCD1/UVSD accumulates in the cytoplasm following microtubule destabilization.
BACKGROUND
DNA structure checkpoints are conserved eukaryotic signal transduction pathways that help preserve genomic integrity. Upon detecting checkpoint signals such as stalled replication forks or double-stranded DNA breaks, these pathways coordinate appropriate stress responses. Members of the PI-3 kinase related kinase (PIKK) family are essential elements of DNA structure checkpoints. In fission yeast, the Rad3 PIKK and its regulatory subunit Rad26 coordinate the detection of checkpoint signals with pathway outputs.


RESULTS
We found that untreated rad26Delta cells were defective for two microtubule-dependent processes: chromosome segregation and morphogenesis. Interestingly, cytoplasmic accumulation of Rad26-GFP occurred following treatment with microtubule destabilizing drugs, but not during treatment with the genotoxic agent Phleomycin. Cytoplasmic accumulation of Rad26-GFP depended on Rad24, a 14-3-3 protein also required for DNA structure checkpoints and morphogenesis. Results of over expression and epistasis experiments confirm that Rad26 and Rad24 define a response to microtubule destabilizing conditions.


CONCLUSIONS
Two DNA structure checkpoint proteins with roles in morphogenesis define a response to microtubule destabilizing conditions.
Baschal
Erin E
EE
University of Colorado at Colorado Springs, Department of Biology, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80918, USA. Erin.Baschal@UCHSC.edu
Chen
Kuan J
KJ
Elliott
Lee G
LG
Herring
Matthew J
MJ
Verde
Shawn C
SC
Wolkow
Tom D
TD
D000199:Actins / Q000032:analysis; D001562:Benzimidazoles / Q000494:pharmacology*; D002219:Carbamates / Q000494:pharmacology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity / Q000187:drug effects; D020090:Chromosome Segregation / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism*; D004249:DNA Damage; D004271:DNA, Fungal / Q000648:ultrastructure; D025141:Drug Resistance, Fungal; D004843:Epistasis, Genetic; D019143:Evolution, Molecular; D018816:Genes, cdc; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000187:drug effects* / Q000648:ultrastructure; D009024:Morphogenesis / Q000235:genetics / Q000502:physiology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010692:Phleomycins / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012568:Schizosaccharomyces / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000187:drug effects / Q000648:ultrastructure; D013827:Thiabendazole / Q000494:pharmacology*; D014170:Transformation, Genetic
D000199:Actins; D001562:Benzimidazoles; D002219:Carbamates; D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D010692:Phleomycins; D029702:Schizosaccharomyces pombe Proteins; C501114:rad24 protein, S pombe; C088086:rad26 protein, S pombe; C006698:carbendazim; D013827:Thiabendazole