Protein ariadne-2 homolog is a protein that in humans is encoded by the ARIH2 gene. [4] [5]
ARIH2 influences development of Mll-Ell-induced acute myeloid leukemia and regulate the proliferation, [6] DNA damage and chemosensitivity of gastric cancer cells by reducing the stability of p21 via ubiquitination, [7] ARIH2 Ubiquitinates NLRP3 and Negatively Regulates NLRP3 Inflammasome Activation in Macrophages. [8]
Deubiquitinating enzymes (DUBs), also known as deubiquitinating peptidases, deubiquitinating isopeptidases, deubiquitinases, ubiquitin proteases, ubiquitin hydrolases, or ubiquitin isopeptidases, are a large group of proteases that cleave ubiquitin from proteins. Ubiquitin is attached to proteins in order to regulate the degradation of proteins via the proteasome and lysosome; coordinate the cellular localisation of proteins; activate and inactivate proteins; and modulate protein-protein interactions. DUBs can reverse these effects by cleaving the peptide or isopeptide bond between ubiquitin and its substrate protein. In humans there are nearly 100 DUB genes, which can be classified into two main classes: cysteine proteases and metalloproteases. The cysteine proteases comprise ubiquitin-specific proteases (USPs), ubiquitin C-terminal hydrolases (UCHs), Machado-Josephin domain proteases (MJDs) and ovarian tumour proteases (OTU). The metalloprotease group contains only the Jab1/Mov34/Mpr1 Pad1 N-terminal+ (MPN+) (JAMM) domain proteases.
ITCH is a HECT domain E3 ubiquitin ligase that is ablated in non-agouti-lethal 18H mice. Itchy mice develop a severe immunological phenotype after birth that includes hyperplasia of lymphoid and hematopoietic cells, and stomach and lung inflammation. In humans ITCH deficiency causes altered physical growth, craniofacial morphology defects, defective muscle development, and aberrant immune system function. ITCH contains a C2 domain, proline-rich region, WW domains, HECT domain, and multiple amino acids that are phosphorylated and ubiquitinated.
E3 ubiquitin-protein ligase NEDD4, also known as neural precursor cell expressed developmentally down-regulated protein 4 is an enzyme that is, in humans, encoded by the NEDD4 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.
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.
DNA damage-binding protein 1 is a protein that in humans is encoded by the DDB1 gene.
Ubiquitin-conjugating enzyme E2 L3 (UBE2L3), also called UBCH7, is a protein that in humans is encoded by the UBE2L3 gene. As an E2 enzyme, UBE2L3 participates in ubiquitination to target proteins for degradation. The role of UBE2L3 in the ubiquitination of the NF-κB precursor implicated it in various major autoimmune diseases, including rheumatoid arthritis (RA), celiac disease, Crohn's disease (CD), and systemic lupus erythematosus.
E3 ubiquitin-protein ligase HUWE1 is an enzyme that in humans is encoded by the HUWE1 gene.
Ubiquitin-conjugating enzyme E2 G2 is a protein that in humans is encoded by the UBE2G2 gene.
E3 ubiquitin-protein ligase RNF216 is an enzyme that in humans is encoded by the RNF216 gene.
Ubiquitin/ISG15-conjugating enzyme E2 L6 is a protein that in humans is encoded by the UBE2L6 gene.
Ubiquitin-conjugating enzyme E2 C is a protein that in humans is encoded by the UBE2C gene.
Ubiquitin conjugation factor E4 B is a protein that in humans is encoded by the UBE4B gene.
Tripartite motif-containing protein 32 is a protein that in humans is encoded by the TRIM32 gene. Since its discovery in 1995, TRIM32 has been shown to be implicated in a number of diverse biological pathways.
E3 ubiquitin-protein ligase RNF8 is an enzyme that in humans is encoded by the RNF8 gene. RNF8 has activity both in immune system functions and in DNA repair.
Ubiquitin conjugation factor E4 A is a protein that in humans is encoded by the UBE4A gene.
Ring finger protein 5 pseudogene 1, also known as RNF5P1, is a human gene.
Mitophagy is the selective degradation of mitochondria by autophagy. It often occurs to defective mitochondria following damage or stress. The process of mitophagy was first described over a hundred years ago by Margaret Reed Lewis and Warren Harmon Lewis. Ashford and Porter used electron microscopy to observe mitochondrial fragments in liver lysosomes by 1962, and a 1977 report suggested that "mitochondria develop functional alterations which would activate autophagy." The term "mitophagy" was in use by 1998.
Linear ubiquitin chain assembly complex (LUBAC) is a multi-protein complex and the only known E3 ubiquitin ligase able to conjugate ubiquitin in a head-to-tail manner to generate linear (M1-linked) polyubiquitin chains. The complex is currently known to be composed of three proteins: heme-oxidized IRP2 ubiquitin ligase 1 (HOIL-1), HOIL-1-interacting protein (HOIP), and Shank-associated RH domain-interacting protein (SHARPIN),,. HOIL-1 and HOIP are both E3 ubiquitin ligases, however, the specific linear ubiquitin-ligating activity is enacted by HOIP. Mice deficient in HOIP are embryonically lethal. Two cases of mutated HOIP have been detected in humans. These patients presented with autoinflammation and immunodeficiency,. HOIL-1 is required for LUBAC assembly and stability as demonstrated by embryonic lethality in HOIL-1 deficient mice. Recently, it has been noted, that HOIL-1 is also able to catalyze formation of oxyester bonds between the C-terminus of ubiquitin and serine/threonine of substrate protein in TLR signaling. SHARPIN exhibits a significant sequence similarity to HOIL-1 and is important for LUBAC stability. Spontaneous point mutation in the Sharpin gene in mice leads to development of chronic proliferative dermatitis (cpdm),. Both HOIL-1 and SHARPIN bind to HOIP through their ubiquitin-like (UBL) domain,. LUBAC consisting of either HOIP-HOIL-1 or HOIP-SHARPIN is functional in vitro, however the greatest activity of the complex has been observed in the presence of all three components.