Substrate-recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. May play a role in accumulation of expanded polyglutamine (polyQ) protein huntingtin (HTT) (By similarity). . This is the function of Ensembl gene identifier ENSG00000147364 (FBXO25, F-box protein 25).