Related Experiment Video
Updated: Aug 22, 2026

Genome-wide Protein-protein Interaction Screening by Protein-fragment Complementation Assay (PCA) in Living Cells
Published on: March 3, 2015
The Aspergillus nidulans npkA gene encodes a Cdc2-related kinase that genetically interacts with the UvsBATR kinase
Marcia R V Z Kress Fagundes1, Joel Fernandes Lima, Marcela Savoldi
1Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil.
Abstract:
The DNA damage response is a protective mechanism that ensures the maintenance of genomic integrity. We have used Aspergillus nidulans as a model system to characterize the DNA damage response caused by the antitopoisomerase I drug, camptothecin. We report the molecular characterization of a p34Cdc2-related gene, npkA, from A. nidulans. The npkA gene is transcriptionally induced by camptothecin and other DNA-damaging agents, and its induction in the presence of camptothecin is dependent on the uvsBATR gene. There were no growth defects, changes in developmental patterns, increased sensitivity to DNA-damaging agents, or effects on septation or growth rate in the A. nidulans npkA deletion strain. However, the DeltanpkA mutation can partially suppress HU sensitivity caused by the DeltauvsBATR and uvsD153ATRIP checkpoint mutations. We demonstrated that the A. nidulans uvsBATR gene is involved in DNA replication and the intra-S-phase checkpoints and that the DeltanpkA mutation can suppress its intra-S-phase checkpoint deficiency. There is a defect in both the intra-S-phase and DNA replication checkpoints due to the npkA inactivation when DNA replication is slowed at 6 mm HU. Our results suggest that the npkA gene plays a role in cell cycle progression during S-phase as well as in a DNA damage signal transduction pathway in A. nidulans.
Related Concept Videos
Anaphase Promoting Complex
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
The Spindle Assembly Checkpoint
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
MAPK Signaling Cascades
