SKP1 is also known as S-phase kinase-associated protein 1A, Cyclin A/CDK2-associated protein p19, p19A, p19skp1, RNA polymerase II elongation factor-like protein, Organ of Corti protein 2, OCP-II protein, OCP-2, Transcription elongation factor B, and SIII. SKP1 is an 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, SKP1 serves as an adapter that links the F-box protein to CUL1. SKP1 interacts directly with CUL1 and F-box proteins, such as BTRC and SKP2, in the SCF complex. SKP1 also interacts with FBX29 and the cyclin A/CDK2 complex. SKP1 is part of a SCF-like complex consisting of CUL7, RBX1, SKP1 and FBXW8 and is also a component of a E3 ubiquitin ligase complex containing UBE2D1, SIAH1, CACYBP/SIP, SKP1A, APC and TBL1X.