5oe7

Structural highlights

Function

[OTUL_HUMAN] Deubiquitinase that specifically removes linear ('Met-1'-linked) polyubiquitin chains to substrates and acts as a regulator of angiogenesis and innate immune response. Associates with the LUBAC complex via direct interaction with RNF31 and counteracts its action by cleaving linear polyubiquitin chains to substrates. Required during angiogenesis, craniofacial and neuronal development by regulating the canonical Wnt signaling together with the LUBAC complex. Acts as a negative regulator of NF-kappa-B by counteracting activity of the LUBAC complex. Plays a key role in innate immune response: required to restrict linear polyubiquitin formation on RIPK2 in response to NOD2 stimulation, probably to limit NOD2-dependent proinflammatory signaling.^{[1] [2] [3] [4]} [UBC_HUMAN] Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.^{[5] [6]}

See Also

• Thioesterase 3D structures
• Ubiquitin

References

1. ↑ Mevissen TE, Hospenthal MK, Geurink PP, Elliott PR, Akutsu M, Arnaudo N, Ekkebus R, Kulathu Y, Wauer T, El Oualid F, Freund SM, Ovaa H, Komander D. OTU Deubiquitinases Reveal Mechanisms of Linkage Specificity and Enable Ubiquitin Chain Restriction Analysis. Cell. 2013 Jul 3;154(1):169-84. doi: 10.1016/j.cell.2013.05.046. PMID:23827681 doi:10.1016/j.cell.2013.05.046
2. ↑ Fiil BK, Damgaard RB, Wagner SA, Keusekotten K, Fritsch M, Bekker-Jensen S, Mailand N, Choudhary C, Komander D, Gyrd-Hansen M. OTULIN restricts Met1-linked ubiquitination to control innate immune signaling. Mol Cell. 2013 Jun 27;50(6):818-30. doi: 10.1016/j.molcel.2013.06.004. PMID:23806334 doi:http://dx.doi.org/10.1016/j.molcel.2013.06.004
3. ↑ Keusekotten K, Elliott PR, Glockner L, Fiil BK, Damgaard RB, Kulathu Y, Wauer T, Hospenthal MK, Gyrd-Hansen M, Krappmann D, Hofmann K, Komander D. OTULIN Antagonizes LUBAC Signaling by Specifically Hydrolyzing Met1-Linked Polyubiquitin. Cell. 2013 Jun 6;153(6):1312-26. doi: 10.1016/j.cell.2013.05.014. PMID:23746843 doi:10.1016/j.cell.2013.05.014
4. ↑ Rivkin E, Almeida SM, Ceccarelli DF, Juang YC, MacLean TA, Srikumar T, Huang H, Dunham WH, Fukumura R, Xie G, Gondo Y, Raught B, Gingras AC, Sicheri F, Cordes SP. The linear ubiquitin-specific deubiquitinase gumby regulates angiogenesis. Nature. 2013 Jun 20;498(7454):318-24. doi: 10.1038/nature12296. Epub 2013 May 24. PMID:23708998 doi:10.1038/nature12296
5. ↑ Huang F, Kirkpatrick D, Jiang X, Gygi S, Sorkin A. Differential regulation of EGF receptor internalization and degradation by multiubiquitination within the kinase domain. Mol Cell. 2006 Mar 17;21(6):737-48. PMID:16543144 doi:S1097-2765(06)00120-1
6. ↑ Komander D. The emerging complexity of protein ubiquitination. Biochem Soc Trans. 2009 Oct;37(Pt 5):937-53. doi: 10.1042/BST0370937. PMID:19754430 doi:10.1042/BST0370937
7. ↑ Weber A, Elliott PR, Pinto-Fernandez A, Bonham S, Kessler BM, Komander D, El Oualid F, Krappmann D. A Linear Diubiquitin-Based Probe for Efficient and Selective Detection of the Deubiquitinating Enzyme OTULIN. Cell Chem Biol. 2017 Aug 28. pii: S2451-9456(17)30280-5. doi:, 10.1016/j.chembiol.2017.08.006. PMID:28919039 doi:http://dx.doi.org/10.1016/j.chembiol.2017.08.006