FBXO15, also known as FBX15, is a 434 amino acid protein that contains one C-terminal F-box domain and belongs to the F-box family of proteins. F-box proteins are critical components of the SCF (Skp1-CUL-1-F-box protein) type E3 ubiquitin ligase complex and are involved in substrate recognition and recruitment for ubiquitination. They are members of a larger family of proteins that are involved in the regulation of a wide variety of cellular processes (including the cell cycle, immune response, signaling cascades and developmental processes) through the targeting of proteins, such as cyclins, cyclin-dependent kinase inhibitors, IkB-a and b-catenin, for degradation by the proteasome after ubiquitination. Via its F-box domain, FBXO15 can directly interact with Skp1 p19 and CUL-1. In addition, FBXO15 is a target of the transcription factor Oct-3 4, however, it does not appear to be essential for early development and fertility.