4tkp

Structural highlights

Function

[UBE2N_HUMAN] The UBE2V1-UBE2N and UBE2V2-UBE2N heterodimers catalyze the synthesis of non-canonical 'Lys-63'-linked polyubiquitin chains. This type of polyubiquitination does not lead to protein degradation by the proteasome. Mediates transcriptional activation of target genes. Plays a role in the control of progress through the cell cycle and differentiation. Plays a role in the error-free DNA repair pathway and contributes to the survival of cells after DNA damage. Acts together with the E3 ligases, HLTF and SHPRH, in the 'Lys-63'-linked poly-ubiquitination of PCNA upon genotoxic stress, which is required for DNA repair. Appears to act together with E3 ligase RNF5 in the 'Lys-63'-linked polyubiquitination of JKAMP thereby regulating JKAMP function by decreasing its association with components of the proteasome and ERAD. Promotes TRIM5 capsid-specific restriction activity and the UBE2V1-UBE2N heterodimer acts in concert with TRIM5 to generate 'Lys-63'-linked polyubiquitin chains which activate the MAP3K7/TAK1 complex which in turn results in the induction and expression of NF-kappa-B and MAPK-responsive inflammatory genes (By similarity).^{[1] [2] [3] [4] [5]} [TRIM5_MACMU] Capsid-specific restriction factor that prevents infection from non-host-adapted retroviruses. Blocks viral replication early in the life cycle, after viral entry but before reverse transcription. In addition to acting as a capsid-specific restriction factor, also acts as a pattern recognition receptor that activates innate immune signaling in response to the retroviral capsid lattice. Binding to the viral capsid triggers its E3 ubiquitin ligase activity, and in concert with the heterodimeric ubiquitin conjugating enzyme complex UBE2V1-UBE2N (also known as UBC13-UEV1A complex) generates 'Lys-63'-linked polyubiquitin chains, which in turn are catalysts in the autophosphorylation of the MAP3K7/TAK1 complex (includes TAK1, TAB2, and TAB3). Activation of the MAP3K7/TAK1 complex by autophosphorylation results in the induction and expression of NF-kappa-B and MAPK-responsive inflammatory genes, thereby leading to an innate immune response in the infected cell. Restricts infection by human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV-agm).^{[6] [7] [8]}

References

1. ↑ Hofmann RM, Pickart CM. Noncanonical MMS2-encoded ubiquitin-conjugating enzyme functions in assembly of novel polyubiquitin chains for DNA repair. Cell. 1999 Mar 5;96(5):645-53. PMID:10089880
2. ↑ Bothos J, Summers MK, Venere M, Scolnick DM, Halazonetis TD. The Chfr mitotic checkpoint protein functions with Ubc13-Mms2 to form Lys63-linked polyubiquitin chains. Oncogene. 2003 Oct 16;22(46):7101-7. PMID:14562038 doi:10.1038/sj.onc.1206831
3. ↑ Tcherpakov M, Delaunay A, Toth J, Kadoya T, Petroski MD, Ronai ZA. Regulation of endoplasmic reticulum-associated degradation by RNF5-dependent ubiquitination of JNK-associated membrane protein (JAMP). J Biol Chem. 2009 May 1;284(18):12099-109. doi: 10.1074/jbc.M808222200. Epub 2009, Mar 6. PMID:19269966 doi:10.1074/jbc.M808222200
4. ↑ David Y, Ziv T, Admon A, Navon A. The E2 ubiquitin conjugating enzymes direct polyubiquitination to preferred lysines. J Biol Chem. 2010 Jan 8. PMID:20061386 doi:M109.089003
5. ↑ Pertel T, Hausmann S, Morger D, Zuger S, Guerra J, Lascano J, Reinhard C, Santoni FA, Uchil PD, Chatel L, Bisiaux A, Albert ML, Strambio-De-Castillia C, Mothes W, Pizzato M, Grutter MG, Luban J. TRIM5 is an innate immune sensor for the retrovirus capsid lattice. Nature. 2011 Apr 21;472(7343):361-5. doi: 10.1038/nature09976. PMID:21512573 doi:10.1038/nature09976
6. ↑ Lienlaf M, Hayashi F, Di Nunzio F, Tochio N, Kigawa T, Yokoyama S, Diaz-Griffero F. Contribution of E3-ubiquitin ligase activity to HIV-1 restriction by TRIM5alpha(rh): structure of the RING domain of TRIM5alpha. J Virol. 2011 Sep;85(17):8725-37. Epub 2011 Jul 6. PMID:21734049 doi:10.1128/JVI.00497-11
7. ↑ Tareen SU, Emerman M. Human Trim5alpha has additional activities that are uncoupled from retroviral capsid recognition. Virology. 2011 Jan 5;409(1):113-20. doi: 10.1016/j.virol.2010.09.018. Epub 2010, Oct 28. PMID:21035162 doi:10.1016/j.virol.2010.09.018
8. ↑ Nakayama EE, Shioda T. TRIM5alpha and Species Tropism of HIV/SIV. Front Microbiol. 2012;3:13. doi: 10.3389/fmicb.2012.00013. Epub 2012 Jan 24. PMID:22291694 doi:10.3389/fmicb.2012.00013