| Structural highlights
Function
[UBB_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.[1] [2] [RD23A_HUMAN] Multiubiquitin chain receptor involved in modulation of proteasomal degradation. Binds to 'Lys-48'-linked polyubiquitin chains in a length-dependent manner and with a lower affinity to 'Lys-63'-linked polyubiquitin chains. Proposed to be capable to bind simultaneously to the 26S proteasome and to polyubiquitinated substrates and to deliver ubiquitinated proteins to the proteasome.[3] [4] [5] [6] [7] Involved in nucleotide excision repair and is thought to be functional equivalent for RAD23B in global genome nucleotide excision repair (GG-NER) by association with XPC. In vitro, the XPC:RAD23A dimer has NER activity. Can stabilize XPC.[8] [9] [10] [11] [12] Involved in vpr-dependent replication of HIV-1 in non-proliferating cells and primary macrophages. Required for the association of HIV-1 vpr with the host proteasome.[13] [14] [15] [16] [17]
Publication Abstract from PubMed
Lanthanoid pseudo-contact shift (PCS) provides long-range structural information between a paramagnetic tag and protein nuclei. However, for proteins with native cysteines, site-specific attachment may only utilize functional groups orthogonal to sulfhydryl chemistry. Here we report two lanthanoid probes, DTTA-C3-yne and DTTA-C4-yne, which can be conjugated to an unnatural amino acid pAzF in the target protein via azide-alkyne cycloaddition. Demonstrated with ubiquitin and cysteine-containing enzyme EIIB, we show that large PCSs of distinct profiles can be generated for each tag/lanthanoid combination. The DTTA-based lanthanoid tags are associated with large magnetic susceptibility tensors owing to the rigidity of the tags. In particular, introduction of the DTTA-C3 tag affords intermolecular PCSs and enables structural characterization of a transient protein complex between ubiquitin and a UBA domain. Together, we have expanded the repertoire of paramagnetic tags and the applicability of paramagnetic NMR.
Lanthanoid tagging via an unnatural amino acid for protein structure characterization.,Jiang WX, Gu XH, Dong X, Tang C J Biomol NMR. 2017 Apr;67(4):273-282. doi: 10.1007/s10858-017-0106-9. Epub 2017, Apr 1. PMID:28365903[18]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ 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
- ↑ 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
- ↑ Sugasawa K, Ng JM, Masutani C, Maekawa T, Uchida A, van der Spek PJ, Eker AP, Rademakers S, Visser C, Aboussekhra A, Wood RD, Hanaoka F, Bootsma D, Hoeijmakers JH. Two human homologs of Rad23 are functionally interchangeable in complex formation and stimulation of XPC repair activity. Mol Cell Biol. 1997 Dec;17(12):6924-31. PMID:9372924
- ↑ Wang Q, Goh AM, Howley PM, Walters KJ. Ubiquitin recognition by the DNA repair protein hHR23a. Biochemistry. 2003 Nov 25;42(46):13529-35. PMID:14621999 doi:10.1021/bi035391j
- ↑ Raasi S, Pickart CM. Rad23 ubiquitin-associated domains (UBA) inhibit 26 S proteasome-catalyzed proteolysis by sequestering lysine 48-linked polyubiquitin chains. J Biol Chem. 2003 Mar 14;278(11):8951-9. PMID:12643283
- ↑ Raasi S, Orlov I, Fleming KG, Pickart CM. Binding of polyubiquitin chains to ubiquitin-associated (UBA) domains of HHR23A. J Mol Biol. 2004 Aug 27;341(5):1367-79. PMID:15321727 doi:10.1016/j.jmb.2004.06.057
- ↑ Li G, Elder RT, Dubrovsky L, Liang D, Pushkarsky T, Chiu K, Fan T, Sire J, Bukrinsky M, Zhao RY. HIV-1 replication through hHR23A-mediated interaction of Vpr with 26S proteasome. PLoS One. 2010 Jun 29;5(6):e11371. doi: 10.1371/journal.pone.0011371. PMID:20614012 doi:10.1371/journal.pone.0011371
- ↑ Sugasawa K, Ng JM, Masutani C, Maekawa T, Uchida A, van der Spek PJ, Eker AP, Rademakers S, Visser C, Aboussekhra A, Wood RD, Hanaoka F, Bootsma D, Hoeijmakers JH. Two human homologs of Rad23 are functionally interchangeable in complex formation and stimulation of XPC repair activity. Mol Cell Biol. 1997 Dec;17(12):6924-31. PMID:9372924
- ↑ Wang Q, Goh AM, Howley PM, Walters KJ. Ubiquitin recognition by the DNA repair protein hHR23a. Biochemistry. 2003 Nov 25;42(46):13529-35. PMID:14621999 doi:10.1021/bi035391j
- ↑ Raasi S, Pickart CM. Rad23 ubiquitin-associated domains (UBA) inhibit 26 S proteasome-catalyzed proteolysis by sequestering lysine 48-linked polyubiquitin chains. J Biol Chem. 2003 Mar 14;278(11):8951-9. PMID:12643283
- ↑ Raasi S, Orlov I, Fleming KG, Pickart CM. Binding of polyubiquitin chains to ubiquitin-associated (UBA) domains of HHR23A. J Mol Biol. 2004 Aug 27;341(5):1367-79. PMID:15321727 doi:10.1016/j.jmb.2004.06.057
- ↑ Li G, Elder RT, Dubrovsky L, Liang D, Pushkarsky T, Chiu K, Fan T, Sire J, Bukrinsky M, Zhao RY. HIV-1 replication through hHR23A-mediated interaction of Vpr with 26S proteasome. PLoS One. 2010 Jun 29;5(6):e11371. doi: 10.1371/journal.pone.0011371. PMID:20614012 doi:10.1371/journal.pone.0011371
- ↑ Sugasawa K, Ng JM, Masutani C, Maekawa T, Uchida A, van der Spek PJ, Eker AP, Rademakers S, Visser C, Aboussekhra A, Wood RD, Hanaoka F, Bootsma D, Hoeijmakers JH. Two human homologs of Rad23 are functionally interchangeable in complex formation and stimulation of XPC repair activity. Mol Cell Biol. 1997 Dec;17(12):6924-31. PMID:9372924
- ↑ Wang Q, Goh AM, Howley PM, Walters KJ. Ubiquitin recognition by the DNA repair protein hHR23a. Biochemistry. 2003 Nov 25;42(46):13529-35. PMID:14621999 doi:10.1021/bi035391j
- ↑ Raasi S, Pickart CM. Rad23 ubiquitin-associated domains (UBA) inhibit 26 S proteasome-catalyzed proteolysis by sequestering lysine 48-linked polyubiquitin chains. J Biol Chem. 2003 Mar 14;278(11):8951-9. PMID:12643283
- ↑ Raasi S, Orlov I, Fleming KG, Pickart CM. Binding of polyubiquitin chains to ubiquitin-associated (UBA) domains of HHR23A. J Mol Biol. 2004 Aug 27;341(5):1367-79. PMID:15321727 doi:10.1016/j.jmb.2004.06.057
- ↑ Li G, Elder RT, Dubrovsky L, Liang D, Pushkarsky T, Chiu K, Fan T, Sire J, Bukrinsky M, Zhao RY. HIV-1 replication through hHR23A-mediated interaction of Vpr with 26S proteasome. PLoS One. 2010 Jun 29;5(6):e11371. doi: 10.1371/journal.pone.0011371. PMID:20614012 doi:10.1371/journal.pone.0011371
- ↑ Jiang WX, Gu XH, Dong X, Tang C. Lanthanoid tagging via an unnatural amino acid for protein structure characterization. J Biomol NMR. 2017 Apr;67(4):273-282. doi: 10.1007/s10858-017-0106-9. Epub 2017, Apr 1. PMID:28365903 doi:http://dx.doi.org/10.1007/s10858-017-0106-9
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