Involved in ubiquitination and subsequent proteasomal degradation of target proteins. Regulator of mitotic processes which plays a role during gametogenesis and embryogenesis. Together with SKP1, RBX1 and a F-box protein, it forms a SCF complex. The functional specificity of this complex depends of the type of F-box protein. SCF(UFO) is implicated in floral organ development. SCF(TIR1) is involved in auxin signaling pathway. SCF(COI1) regulates responses to jasmonates. SCF(EID1) and SCF(AFR) are implicated in phytochrome A light signaling. SCF(ADO1/ZTL), SCF(ADO2/LKP2), SCF(ADO3/FKF1) are related to the circadian clock. SCF(ORE9) seems to be involved in senescence. SCF(EBF1/EBF2) may regulate ethylene signaling. Protein modification; protein ubiquitination. Part of E3 ubiquitin ligase SCF complexes such as SCF(TIR1) and SCF(COI1). SCF(TIR1) is composed of CUL1, SKP1 (SKP1A or SKP1B), RBX1 (RBX1A or RBX1B) and TIR1, while SCF(COI1) is composed of CUL1, SKP1, RBX1 and COI1. A SNF1-related protein kinase (KIN10 and KIN11) can also be part of these SCF complexes. SCF(TIR1) is able to interact with the COP9 signalosome (CSN) complex. Interacts directly with some F-box proteins such as DOR, SKIP14, FBW2/SKIP18, SKIP19/FBL20 and SKIP28/MEE11. Interacts with CAND1. Mainly nuclear during interphase and preprophase, but also weakly cytoplasmic during interphase. Associated to mitotic spindle during metaphase, and to the phragmoplast during telophase. Expressed constitutively in roots, seedlings, stems, leaves and flowers. Strong accumulation in embryos (at protein level). Neddylated (rubylated). Deneddylation occurs upon interaction with the COP9 signalosome (CSN) complex. Belongs to the cullin family.