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F-box only protein 5; early mitotic inhibitor 1 (FBXO5, EMI1, FBX5)
Function:
- regulates progression through early mitosis by inhibiting the anaphase promoting complex/cyclosome (APC)
- binds to the APC activators CDC20 & FZR1/CDH1 to prevent APC activation
- can also bind directly to the APC to inhibit substrate-binding
- phosphorylation by CDK2 & subsequently by PLK1 triggers degradation during early mitosis through ubiquitin-mediated proteolysis by the SCF ubiquitin ligase complex containing the F-box protein BTRC; this degradation is necessary for activation of APC in late mitosis & subsequent mitotic progression
- part of a SCF complex (putative)
- interacts with BTRC, FZR1/CDH1 & the N-terminal substrate- binding domain of CDC20
- also interacts with EVI5 which blocks its phosphorylation by PLK1 & prevents its subsequent binding to BTRC & degradation
Structure:
- the C-terminal region is required for inhibition of APC activity
- contains 1 F-box domain
- contains 1 IBR-type Zn+2 finger
Compartment:
- nucleus, cytoplasm, cytoskeleton, spindle
- in interphase, localizes in a punctate manner in the nucleus & cytoplasm with some perinuclear concentration
- in mitotic cells, localizes throughout the cell, particularly at the spindle
Expression:
- accumulates in late G1 phase, levels rise during S phase & drop in early mitosis
General
F-box only protein
zinc finger protein
Properties
SIZE: entity length = 447 aa
MW = 50 kD
COMPARTMENT: cytoplasm
cell nucleus
MOTIF: EVI5 interaction {135-244}
F-box domain {250-296}
Zinc finger
NAME: Zinc finger
SITE: 357-419
EFFECTOR-BOUND: Zn+2
Database Correlations
OMIM 606013
UniProt Q9UKT4
Pfam PF00646
Entrez Gene 26271
Kegg hsa:26271
References
OMIM :accession 606013