Related Experiment Videos
20S cyclosome complex formation and proteolytic activity inhibited by the cAMP/PKA pathway
Y M Yamashita1, Y Nakaseko, I Samejima
1Department of Biophysics, Graduate School of Science, Kyoto University, Japan.
Nature
|November 21, 1996
Summary
Cut4 is essential for the 20S cyclosome complex (anaphase-promoting complex) function in fission yeast. The cAMP/PKA pathway inhibits cyclosome formation and activation, impacting mitosis.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- The 20S cyclosome complex, or anaphase-promoting complex, is crucial for cell cycle progression, mediating mitotic cyclin destruction and sister chromatid separation.
- The precise regulatory mechanisms governing the formation and activation of the 20S cyclosome complex remain largely unknown.
Purpose of the Study:
- To identify essential components of the 20S cyclosome complex in fission yeast.
- To elucidate the regulatory pathways controlling 20S cyclosome complex formation and activation.
Main Methods:
- Genetic analysis of the cut4 gene in fission yeast.
- Biochemical assays to assess 20S complex integrity and ubiquitination activity.
- Phenotypic analysis of cut4 mutants, including stress sensitivity and cell cycle progression.
Main Results:
- Cut4 was identified as an essential component of the 20S cyclosome complex in fission yeast.
- Mutations in cut4 led to defects in mitotic cyclin ubiquitination, anaphase onset, and 20S complex disruption.
- The observed phenotypes were suppressed by components of the cAMP/protein kinase A (PKA) pathway, suggesting its inhibitory role.
Conclusions:
- The cAMP/PKA pathway negatively regulates the formation and activation of the 20S cyclosome complex.
- Cut4 plays a critical role in maintaining 20S cyclosome complex integrity and function during mitosis.