Human CUL1 forms an evolutionarily conserved ubiquitin ligase complex (SCF) with SKP1 and an F-box protein
Open Access
- 23 June 1998
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 95 (13), 7451-7456
- https://doi.org/10.1073/pnas.95.13.7451
Abstract
The SCF ubiquitin ligase complex of budding yeast triggers DNA replication by catalyzing ubiquitination of the S phase cyclin-dependent kinase inhibitor SIC1. SCF is composed of three proteins—ySKP1, CDC53 (Cullin), and the F-box protein CDC4—that are conserved from yeast to humans. As part of an effort to identify components and substrates of a putative human SCF complex, we isolated hSKP1 in a two-hybrid screen with hCUL1, the closest human homologue of CDC53. Here, we show that hCUL1 associates with hSKP1 in vivo and directly interacts with both hSKP1 and the human F-box protein SKP2 in vitro, forming an SCF-like particle. Moreover, hCUL1 complements the growth defect of yeast cdc53ts mutants, associates with ubiquitination-promoting activity in human cell extracts, and can assemble into functional, chimeric ubiquitin ligase complexes with yeast SCF components. Taken together, these data suggest that hCUL1 functions as part of an SCF ubiquitin ligase complex in human cells. Further application of biochemical assays similar to those described here can now be used to identify regulators/components of hCUL1-based SCF complexes, to determine whether the hCUL2–hCUL5 proteins also are components of ubiquitin ligase complexes in human cells, and to screen for chemical compounds that modulate the activities of the hSKP1 and hCUL1 proteins.Keywords
This publication has 38 references indexed in Scilit:
- Anaphase initiation in Saccharomyces cerevisiae is controlled by the APC-dependent degradation of the anaphase inhibitor Pds1p.Genes & Development, 1996
- Turnover of cyclin E by the ubiquitin-proteasome pathway is regulated by cdk2 binding and cyclin phosphorylation.Genes & Development, 1996
- Cdc53 Targets Phosphorylated G1 Cyclins for Degradation by the Ubiquitin Proteolytic PathwayCell, 1996
- SKP1 Connects Cell Cycle Regulators to the Ubiquitin Proteolysis Machinery through a Novel Motif, the F-BoxCell, 1996
- Rapid Degradation of the G 1 Cyclin Cln2 Induced by CDK-Dependent PhosphorylationScience, 1996
- Rel/NF-kappa B/I kappa B family: intimate tales of association and dissociation.Genes & Development, 1995
- Role of the Ubiquitin-Proteasome Pathway in Regulating Abundance of the Cyclin-Dependent Kinase Inhibitor p27Science, 1995
- Protein ubiquitination involving an E1–E2–E3 enzyme ubiquitin thioester cascadeNature, 1995
- Differential regulation of E2F transactivation by cyclin/cdk2 complexes.Genes & Development, 1994
- A novel genetic system to detect protein–protein interactionsNature, 1989