title: FBXO5
text: # FBXO5
  
  F-box only protein 5 is a protein that in humans is encoded by the FBXO5 gene.
  
  ## Function
  
  This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of the ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbxs class. This protein is similar to xenopus early mitotic inhibitor-1 (Emi1), which is a mitotic regulator that interacts with Cdc20 and inhibits the anaphase promoting complex. Moreover, Emi1 also assembles a CRL1 complex that targets RAD51 for ubiquitin-mediated degradation.
  
  ## Disease
  
  Gene and protein expression of FBXO5/Emi1 are increased in many human cancers and increased expression has been shown to cause chromosome instability and cancer.
  
  ## Interactions
  
  FBXO5 has been shown to interact with:
  
  * CDC20,
  * FZR1,
  * SKP1A. and
  * RAD51.
  