Related Experiment Video
Updated: Jul 17, 2026

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins
Published on: August 9, 2019
Caf1 regulates translocation of ribonucleotide reductase by releasing nucleoplasmic Spd1-Suc22 assembly
Shinya Takahashi1, Kenji Kontani, Yasuhiro Araki
1Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan.
Abstract:
Appropriate supply of deoxyribonucleotides by the ribonucleotide reductase (RNR) complex is essential for DNA replication and repair. One recent model for the RNR activation in Schizosaccharomyces pombe is translocation of the regulatory subunit Suc22 from the nucleoplasm to the cytoplasm. The RNR inhibitory protein Spd1, which retains Suc22 in the nucleoplasm, is rapidly degraded upon DNA-replication stress, resulting in release of Suc22 to form the active RNR complex in the cytoplasm. Here, we show that Caf1, a component of the Ccr4-Not complex, is responsible for resistance of the replication stress and control of the Suc22 translocation. Caf1 is required not only for the stress-induced translocation of Suc22 from nucleoplasm to cytoplasm but also for the degradation of nucleoplasmic Spd1. DNA-replication stress appears to allow Caf1 to interact with Suc22, resulting in release of the nucleoplasmic Spd1-Suc22 assembly. Taken together, these results suggest a novel function of Caf1 as a key regulator in the stress-induced RNR activation.
More Related Videos
10:27Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
Published on: March 9, 2012
10:50Using In Vitro Fluorescence Resonance Energy Transfer to Study the Dynamics Of Protein Complexes at a Millisecond Time Scale
Published on: March 14, 2019
Related Concept Videos
Regulation of Nuclear Protein Sorting
Directing Proteins to the Rough Endoplasmic Reticulum
Cotranslational Protein Translocation
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Directionality of Nuclear Transport
Rab Cascades
Post-translational Translocation of Proteins to the RER
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...