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. In the SCF complex, serves as an adapter that links the F-box protein to CUL1. The functional specificity of the SCF complex depends on the F-box protein as substrate recognition component. SCF(BTRC) and SCF(FBXW11) direct ubiquitination of CTNNB1 and participate in Wnt signaling. SCF(FBXW11) directs ubiquitination of phosphorylated NFKBIA. SCF(BTRC) directs ubiquitination of NFKBIB, NFKBIE, ATF4, SMAD3, SMAD4, CDC25A, FBXO5, CEP68 and probably NFKB2. SCF(SKP2) directs ubiquitination of phosphorylated CDKN1B/p27kip and is involved in regulation of G1/S transition. SCF(SKP2) directs ubiquitination of ORC1, CDT1, RBL2, ELF4, CDKN1A, RAG2, FOXO1A, and probably MYC and TAL1. SCF(FBXW7) directs ubiquitination of cyclin E, NOTCH1 released notch intracellular domain (NICD), and probably PSEN1. SCF(FBXW2) directs ubiquitination of GCM1. SCF(FBXO32) directs ubiquitination of MYOD1. SCF(FBXO7) directs ubiquitination of BIRC2 and DLGAP5. SCF(FBXO33) directs ubiquitination of YBX1. SCF(FBXO11) directs ubiquitination of BCL6 and DTL but does not seem to direct ubiquitination of TP53. SCF(BTRC) mediates the ubiquitination of NFKBIA at 'Lys-21' and 'Lys-22'; the degradation frees the associated NFKB1-RELA dimer to translocate into the nucleus and to activate transcription. SCF(CCNF) directs ubiquitination of CCP110. SCF(FBXL3) and SCF(FBXL21) direct ubiquitination of CRY1 and CRY2. SCF(FBXO9) directs ubiquitination of TTI1 and TELO2. SCF(FBXO10) direct ubiquitination of BCL2. Protein modification; protein ubiquitination. Interacts with KDM2B, forming heterodimers (By similarity). The KDM2B-SKP1 heterodimeric complex interacts with the PCGF1-BCORL heterodimeric complex to form a homotetrameric polycomb repression complex 1 (PRC1.1) (By similarity). Component of multiple SCF (SKP1-CUL1-F-box) E3 ubiquitin-protein ligase complexes formed of CUL1, SKP1, RBX1 and a variable F-box domain-containing protein as substrate-specific subunit. Component of the SCF(FBXW11) complex containing FBXW11. Component of the SCF(SKP2) complex containing SKP2, in which it interacts directly with SKP1, SKP2 and RBX1. Component of the SCF(FBXW2) complex containing FBXw2. Component of the SCF(FBXO32) complex containing FBXO32. Component of the probable SCF(FBXO7) complex containing FBXO7. Component of the SCF(FBXO10) complex containing FBXO10. Component of the SCF(FBXO11) complex containing FBXO11. Component of the SCF(FBXO25) complex containing FBXO25. Component of the SCF(FBXO33) complex containing FBXO33. Component of the probable SCF(FBXO4) complex containing FBXO4. Component of the SCF(FBXO44) complex, composed of SKP1, CUL1 and FBXO44. Component of the SCF(BTRC) complex, composed of SKP1, CUL1 and BTRC. This complex binds phosphorylated NFKBIA. Part of a SCF complex consisting of CUL1, RBX1, SKP1 and FBXO2. Component of a SCF(SKP2)-like complex containing CUL1, SKP1, TRIM21 and SKP2. Component of the SCF(FBXO17) complex, composed of SKP1, CUL1 and FBXO17. Component of the SCF(FBXO27) complex, composed of SKP1, CUL1 and FBXO27. Component of the SCF(CCNF) complex consisting of CUL1, RBX1, SKP1 and CCNF. Component of the SCF(FBXL3) complex composed of CUL1, SKP1, RBX1 and FBXL3. Component of the SCF(FBXL21) complex composed of CUL1, SKP1, RBX1 and FBXL21. Component of the SCF(FBXO9) composed of CUL1, SKP1, RBX1 and FBXO9. Component of the SCF(FBXW7) composed of CUL1, SKP1, RBX1 and FBXW7. Interacts with CEP68 (By similarity). Interacts with NOTCH2 and FBXW15 (By similarity). The SKP1-KDM2A and SKP1-KDM2B complexes interact with UBB (By similarity). Undergoes autophagy-mediated degradation in the liver in a time-dependent manner. Belongs to the SKP1 family.