RING-box protein 1 is a protein that in humans is encoded by the RBX1 gene. [4] [5]
This gene encodes an evolutionarily conserved protein that interacts with cullins. The protein plays a unique role in the ubiquitination reaction by heterodimerizing with cullin-1 to catalyze ubiquitin polymerization. It also may be involved in the regulation of protein turn-over. [6]
RBX1 has been shown to interact with:
S-phase kinase-associated protein 2 is an enzyme that in humans is encoded by the SKP2 gene.
Cullin 1, also known as CUL1, is a human protein and gene from cullin family. This protein plays an important role in protein degradation and protein ubiquitination.
NEDD8 is a protein that in humans is encoded by the NEDD8 gene. This ubiquitin-like (UBL) protein becomes covalently conjugated to a limited number of cellular proteins, in a process called NEDDylation similar to ubiquitination. Human NEDD8 shares 60% amino acid sequence identity to ubiquitin. The primary known substrates of NEDD8 modification are the cullin subunits of cullin-based E3 ubiquitin ligases, which are active only when NEDDylated. Their NEDDylation is critical for the recruitment of E2 to the ligase complex, thus facilitating ubiquitin conjugation. NEDD8 modification has therefore been implicated in cell cycle progression and cytoskeletal regulation.
Elongin B is a protein that in humans is encoded by the ELOB gene.
Cullin-4A is a protein that in humans is encoded by the CUL4A gene. CUL4A belongs to the cullin family of ubiquitin ligase proteins and is highly homologous to the CUL4B protein. CUL4A regulates numerous key processes such as DNA repair, chromatin remodeling, spermatogenesis, haematopoiesis and the mitotic cell cycle. As a result, CUL4A has been implicated in several cancers and the pathogenesis of certain viruses including HIV. A component of a CUL4A complex, Cereblon, was discovered to be a major target of the teratogenic agent thalidomide.
F-box/WD repeat-containing protein 7 is a protein that in humans is encoded by the FBXW7 gene.
Cullin-5 is a protein that in humans is encoded by the CUL5 gene.
CDC34 is a gene that in humans encodes the protein Ubiquitin-conjugating enzyme E2 R1. This protein is a member of the ubiquitin-conjugating enzyme family, which catalyzes the covalent attachment of ubiquitin to other proteins.
Cullin-2 is a protein that in humans is encoded by the CUL2 gene.
Cullin-4B is a protein that in humans is encoded by the CUL4B gene which is located on the X chromosome. CUL4B has high sequence similarity with CUL4A, with which it shares certain E3 ubiquitin ligase functions. CUL4B is largely expressed in the nucleus and regulates several key functions including: cell cycle progression, chromatin remodeling and neurological and placental development in mice. In humans, CUL4B has been implicated in X-linked intellectual disability and is frequently mutated in pancreatic adenocarcinomas and a small percentage of various lung cancers. Viruses such as HIV can also co-opt CUL4B-based complexes to promote viral pathogenesis. CUL4B complexes containing Cereblon are also targeted by the teratogenic drug thalidomide.
Cullin 3 is a protein that in humans is encoded by the CUL3 gene.
RING-box protein 2 is a protein that in humans is encoded by the RNF7 gene.
Cullin-associated NEDD8-dissociated protein 1 is a protein that in humans is encoded by the CAND1 gene.
F-box only protein 4 is a protein that in humans is encoded by the FBXO4 gene.
F-box only protein 2 is a protein that in humans is encoded by the FBXO2 gene.
F-box/WD repeat-containing protein 8 is a protein that in humans is encoded by the FBXW8 gene.
Cullins are a family of hydrophobic scaffold proteins which provide support for ubiquitin ligases (E3). All eukaryotes appear to have cullins. They combine with RING proteins to form Cullin-RING ubiquitin ligases (CRLs) that are highly diverse and play a role in myriad cellular processes, most notably protein degradation by ubiquitination.
S-phase kinase-associated protein 1 is an enzyme that in humans is encoded by the SKP1 gene.
F-box and leucine-rich repeat protein 4 is a protein that in humans is encoded by the FBXL4 gene.
F-box protein 40 is a protein that in humans is encoded by the FBXO40 gene. Fbxo40 induces ubiquitination of IRS1, thus limiting activity of IGF1 signaling.