The USP20 gene is located on chromosome 9 at the locus 9q34.11.[6][11]
Structure
USP20 is a 914-amino acid protein that shows 59% homology with another DUB, USP33.[12] It contains 4 known domains, an N-terminal Zf UBP domain, a catalytic domain containing conserved histidine and cysteine residues, and two C-terminal DUSP domains.[13]
Function
DUBs are categorised into 5 main groups, ubiquitin-specific proteases (USP), ubiquitin c-terminal hydrolases (UCH), ovarian tumour proteases (OTU), Machado-Joseph disease proteases (MJD), and JAB1/MPN/MOV34 proteases (JAMM/MPN+). The first four groups are cysteine proteases, whereas the last group are Zn metalloproteases. USP20 belongs to the USP group and, like most DUBs, catalyse the breakage of an isopeptide bond between a lysine residue of the target protein and the terminal glycine residue of a ubiquitin protein. This occurs via a conserved cysteine and histidine residue in the catalytic site of the enzyme. The histidine molecule is protonated by the cysteine residue and this allows the cystein residue to undergo a nucleophilic attack on the isopeptide bond, which removes the ubiquitin from the substrate protein.[14]
Thyronine deiodinase type 2
USP20 deubiquitinates thyronine deiodinase type 2 (D2), an enzyme that converts thyroxine (T4) into active 3,5,3'-triiodothyronine (T3). D2 is ubiquitinated after binding of T4, which signals for the degradation of D2 via the proteasome and also causes an inactivating conformational change of the protein. Deubiquitination by USP20 rescues D2 from degradation and also returns D2 to its active conformation.[8][15]
USP20 is involved in the recycling of the β2-adrenergic receptor. After agonist stimulation, the receptor is internalised and ubiquitinated. USP20 serves to deubiquitinate the receptor and prevent its degradation by the proteasome. This allows it to be recycled to the cell surface in order to resensitize the cell to signalling molecules.[10]
Regulation
In addition to the regulation of HIF1α, pVHL regulates USP20. USP20 binds to the β-domain of pVHL and is subsequently ubiquitinated. This signals USP20 for degradation via the proteasome.[12]
^Komander D, Clague MJ, Urbé S (Aug 2009). "Breaking the chains: structure and function of the deubiquitinases". Nature Reviews. Molecular Cell Biology. 10 (8): 550–63. doi:10.1038/nrm2731. PMID19626045. S2CID19149247.
^ abLi Z, Wang D, Na X, Schoen SR, Messing EM, Wu G (Jun 2002). "Identification of a deubiquitinating enzyme subfamily as substrates of the von Hippel-Lindau tumor suppressor". Biochemical and Biophysical Research Communications. 294 (3): 700–9. doi:10.1016/S0006-291X(02)00534-X. PMID12056827.
Li Z, Wang D, Na X, Schoen SR, Messing EM, Wu G (Jun 2002). "Identification of a deubiquitinating enzyme subfamily as substrates of the von Hippel-Lindau tumor suppressor". Biochemical and Biophysical Research Communications. 294 (3): 700–9. doi:10.1016/S0006-291X(02)00534-X. PMID12056827.
Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.
The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.