Cell Division Cycle Protein 34 (CDC34)

Ubiquitin-conjugating enzyme E2 R1 is a member of the ubiquitin-conjugating enzyme family. Ubiquitin-conjugating enzyme catalyzes the covalent attachment of ubiquitin to other proteins. This protein is a part of the large multiprotein complex, which is required for ubiquitin-mediated degradation of cell cycle G1 regulators, and for the initiation of DNA replication.

In vitro binding experiments demonstrated that phosphorylated UBC3B and CDC34 bound specifically to the F-box protein beta-TRCP (BTRC), which resulted in enhanced degradation of beta-catenin, a substrate of BTRC. Semplici et al. (2002) suggested that CK2-dependent phosphorylation of CDC34 and UBC3B functions by regulating BTRC substrate recognition.