Regulation of Cullin RING Ligases

• Published in: Annual review of plant biology 2008-01, Vol.59 (1), p.467-489
• Main Authors: Hotton, S.K, Callis, J
• Format: Article
• Language: English
• Subjects: Arabidopsis - metabolism; Arabidopsis Proteins - metabolism; biochemical pathways; Botany; cell nucleus; Cells; chemical bonding; Cullin Proteins - metabolism; cullin RING ligases; cytosol; derubylation; enzyme activity; enzyme substrates; Enzymes; ligases; Ligases - metabolism; literature reviews; plant development; plant hormones; plant proteins; Plant Proteins - metabolism; plants; Proteasome Endopeptidase Complex - metabolism; proteasomes; Protein Binding; protein structure; protein subunits; protein-protein interactions; Proteins; proteolysis; rubylation; ubiquitin; Ubiquitin - metabolism; ubiquitin-like proteins
• ISSN: 1543-5008; 1545-2123
• DOI: 10.1146/annurev.arplant.58.032806.104011

The ubiquitin/26S proteasome pathway largely mediates selective proteolysis in the nucleus and cytosol. This pathway catalyzes covalent attachment of ubiquitin (UBQ) to substrate proteins in an E1-E2-E3 cascade. Ubiquitin E3 ligases interact with substrates to catalyze UBQ transfer from E2 to substrate. Within the E3 ligase superfamily, cullin RING ligases (CRLs) are significant in plants because they are linked to hormonal signaling, developmental programs, and environmental responses. Thus, knowledge of CRL regulation is required for a complete understanding of these processes. A major mechanism modulating CRL activity is modification of the cullin subunit by RUB (RELATED TO UBIQUITIN), a ubiquitin-like protein, and demodification by the COP9 signalosome (CSN). CULLIN-ASSOCIATED NEDD8-DISSOCIATED 1 (CAND1) interacts with CRLs, affecting both rubylation and derubylation. Described here are the pathways, regulation, and biological function of rubylation and derubylation, as well as future directions and outstanding questions.