InterPro domain: IPR016897

This entry includes SKP1 from yeasts, animals and plants.

Mammlian S-phase kinase-associated protein 1 (SKP1) is an essential component of the SCF (SKP1-CUL1-F-box protein) ubiquitin ligase complex, which mediates the ubiquitination of proteins involved in cell cycle progression, signal transduction and transcription [ 1 ]. It is also part of the ubiquitin E3 ligase complex (Skp1-Pam-Fbxo45) that controls the core epithelial-to-mesenchymal transition-inducing transcription factors [ 2 ].

Budding yeast Skp1 is a kinetochore protein found in several complexes, including the SCF ubiquitin ligase complex, the CBF3 complex that binds centromeric DNA [ 3 ], and the RAVE complex that regulates assembly of the V-ATPase [ 4 ]. In Dictyostelium discoideum (Slime mold) FP21 was shown to be glycosylated in the cytosol and has homology to SKP1 [ 5 ].

Arabidopsis Skp1 is part of the Skp1/Cullin1/F-box protein COI1 (SCFCOI1) E3 ubiquitin ligase complex required for vegetative and floral organ development as well as for male gametogenesis [ 6 , 7 ]. 21 Skp1-related genes, called Arabidopsis-SKP1-like (ASK), have been uncovered in the Arabidopsis genome. They may collectively perform a range of functions and may regulate different developmental and physiological processes [ 8 , 9 ].

1. Structural basis of dimerization-dependent ubiquitination by the SCF(Fbx4) ubiquitin ligase. J. Biol. Chem. 285, 13896-906
2. Atypical ubiquitin E3 ligase complex Skp1-Pam-Fbxo45 controls the core epithelial-to-mesenchymal transition-inducing transcription factors. Oncotarget 6, 979-94
3. The Saccharomyces cerevisiae kinetochore contains a cyclin-CDK complexing homologue, as identified by in vitro reconstitution. EMBO J. 15, 3611-20
4. Skp1 forms multiple protein complexes, including RAVE, a regulator of V-ATPase assembly. Nat. Cell Biol. 3, 384-91
5. Characterization of FP21, a cytosolic glycoprotein from Dictyostelium. J. Biol. Chem. 270, 3022-30
6. The RING E3 ligase KEEP ON GOING modulates JAZ12 stability. Plant Physiol. 25, 209-23
7. The ASK1 gene regulates development and interacts with the UFO gene to control floral organ identity in Arabidopsis. Dev. Genet. 133, 203-17
8. Members of the Arabidopsis-SKP1-like gene family exhibit a variety of expression patterns and may play diverse roles in Arabidopsis. Plant Physiol. 7, e50984
9. The SKP1-like gene family of Arabidopsis exhibits a high degree of differential gene expression and gene product interaction during development. PLoS ONE