Involved in ubiquitination and subsequent proteasomal degradation of target proteins. Together with CUL1, RBX1 and a F-box protein, it forms a SCF E3 ubiquitin ligase complex. The functional specificity of this complex depends on the type of F-box protein. In the SCF complex, it serves as an adapter that links the F-box protein to CUL1 (By similarity). Protein modification; protein ubiquitination. Part of a SCF (SKP1-cullin-F-box) protein ligase complex (By similarity). Interacts with At1g56610, At1g67340, At3g62230, At3g59000, At4g27050, At1g55000, SKIP16 and SKIP32. Mostly expressed in inflorescence and siliques, and, to a lower extent, in seedlings, roots, and stems. Detected throughout the inflorescence at a higher level in the inflorescence meristem (IM) than in the young flower. Very strongly expressed in the valve, septum, and developing seed. Also present in pollen grains. Belongs to the SKP1 family.