CUL2

CUL2 Full Name

cullin 2

CUL2 Introduction

CUL2 (Cullin 2) is a core scaffold protein of the Cullin-RING E3 ubiquitin ligase (CRL2) family, playing a central role in targeted protein ubiquitination and degradation. It forms the structural backbone of CRL2 complexes by associating with adaptor proteins Elongin B/C, the RING protein Rbx1, and substrate recognition modules such as VHL-box containing receptors. Through these interactions, CUL2 orchestrates the recruitment of substrates for ubiquitination, which is subsequently facilitated by E2 ubiquitin-conjugating enzymes. The enzymatic activity of CRL2 complexes is tightly regulated by NEDD8 modification, which induces conformational rearrangements, enhances E2 enzyme recruitment, and ultimately ensures efficient ubiquitin transfer. This precise control mechanism underlines CUL2's fundamental role in maintaining protein homeostasis, signaling fidelity, and regulated cellular processes.

Functionally, CUL2-mediated CRL2 complexes are involved in a broad spectrum of cellular activities, including DNA replication, transcription regulation, cell cycle progression, developmental pathways, circadian rhythm maintenance, and stress response modulation. By targeting specific substrates for ubiquitin-dependent proteasomal degradation, CUL2 helps eliminate misfolded or damaged proteins, modulate signaling cascades, and coordinate key cellular responses to environmental cues. Notably, the CRL2 family, with CUL2 as a scaffold, is estimated to regulate up to 20% of the cellular proteome, reflecting its extensive influence across diverse physiological and cellular networks. CUL2's involvement in apoptosis, stress response, and viral modulation further highlights its multifunctional role in maintaining cellular homeostasis.

From a disease perspective, dysregulation of CUL2 and CRL2 activity has been implicated in multiple pathologies, including metabolic disorders, cancer, and developmental abnormalities. Targeting CUL2-containing CRL2 complexes, particularly through the VHL/CUL2 module, has become a promising therapeutic strategy, exemplified by the development of small-molecule inhibitors and PROTACs aimed at selective protein degradation. Given its central position in ubiquitin-mediated proteolysis, CUL2 represents a critical node for drug discovery, where modulating its activity could restore proteostasis, inhibit aberrant signaling, or degrade disease-driving proteins. The expanding structural and functional insights into CUL2 and its complexes provide a solid foundation for the design of novel targeted therapies, emphasizing its relevance for translational research and clinical applications.

Alternate Names for CUL2

CUL2; cullin 2; cullin-2; CUL-2; MGC131970;

• 1.Jeong Y, et al.; Targeting E3 ubiquitin ligases and their adaptors as a therapeutic strategy for metabolic diseases. Exp Mol Med. 2023, 55(10):2097-2104.
  2.Diehl CJ, Ciulli A. Discovery of small molecule ligands for the von Hippel-Lindau (VHL) E3 ligase and their use as inhibitors and PROTAC degraders. Chem Soc Rev. 2022, 51(19):8216-8257.