Structural highlights
Function
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).[1] [2] [3]
References
- ↑ 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
- ↑ 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
- ↑ 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