| Structural highlights
Function
[MU1_REOVL] Major outer capsid protein involved in host cell membrane penetration. In the endocytic compartment, outer-capsid protein sigma-3 is removed by cathepsin proteases, which exposes the viral membrane-penetration protein mu-1. Both myristoylated peptides mu-1N and phi are released during infectious subvirion particles (ISVP) formation in the endosome. They associate with host membranes and mu-1N induces permeabilization and delivery of transcriptionally active viral particles into the host cell cytoplasm. Seems to induce apoptosis in the host cell.[1] [2] [3] [4] [5] The viral outer shell polypeptides, of which mu-1 is one, impose structural constraints that prevent elongation of nascent transcripts by the RNA-dependent RNA polymerase lambda-3.[6] [7] [8] [9] [10]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Cell entry by nonenveloped animal viruses requires membrane penetration without membrane fusion. The reovirus penetration agent is the outer-capsid protein, Mu1. The structure of Mu1, complexed with its "protector" protein, Sigma3, and the fit of this Mu1(3)Sigma3(3) heterohexameric complex into the cryoEM image of an intact virion, reveal molecular events essential for viral penetration. Autolytic cleavage divides Mu1 into myristoylated Mu1N and Mu1C. A long hydrophobic pocket can receive the myristoyl group. Dissociation of Mu1N, linked to a major conformational change of the entire Mu1 trimer, must precede myristoyl-group insertion into the cellular membrane. A myristoyl switch, coupling exposure of the fatty acid chain, autolytic cleavage of Mu1N, and long-range molecular rearrangement of Mu1C, thus appears to be part of the penetration mechanism.
Structure of the reovirus membrane-penetration protein, Mu1, in a complex with is protector protein, Sigma3.,Liemann S, Chandran K, Baker TS, Nibert ML, Harrison SC Cell. 2002 Jan 25;108(2):283-95. PMID:11832217[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Farsetta DL, Chandran K, Nibert ML. Transcriptional activities of reovirus RNA polymerase in recoated cores. Initiation and elongation are regulated by separate mechanisms. J Biol Chem. 2000 Dec 15;275(50):39693-701. PMID:11007773 doi:http://dx.doi.org/10.1074/jbc.M004562200
- ↑ Odegard AL, Chandran K, Zhang X, Parker JS, Baker TS, Nibert ML. Putative autocleavage of outer capsid protein micro1, allowing release of myristoylated peptide micro1N during particle uncoating, is critical for cell entry by reovirus. J Virol. 2004 Aug;78(16):8732-45. PMID:15280481 doi:http://dx.doi.org/10.1128/JVI.78.16.8732-8745.2004
- ↑ Coffey CM, Sheh A, Kim IS, Chandran K, Nibert ML, Parker JS. Reovirus outer capsid protein micro1 induces apoptosis and associates with lipid droplets, endoplasmic reticulum, and mitochondria. J Virol. 2006 Sep;80(17):8422-38. PMID:16912293 doi:http://dx.doi.org/80/17/8422
- ↑ Zhang L, Chandran K, Nibert ML, Harrison SC. Reovirus mu1 structural rearrangements that mediate membrane penetration. J Virol. 2006 Dec;80(24):12367-76. Epub 2006 Sep 27. PMID:17005655 doi:http://dx.doi.org/10.1128/JVI.01343-06
- ↑ Ivanovic T, Agosto MA, Zhang L, Chandran K, Harrison SC, Nibert ML. Peptides released from reovirus outer capsid form membrane pores that recruit virus particles. EMBO J. 2008 Apr 23;27(8):1289-98. Epub 2008 Mar 27. PMID:18369316 doi:http://dx.doi.org/emboj200860
- ↑ Farsetta DL, Chandran K, Nibert ML. Transcriptional activities of reovirus RNA polymerase in recoated cores. Initiation and elongation are regulated by separate mechanisms. J Biol Chem. 2000 Dec 15;275(50):39693-701. PMID:11007773 doi:http://dx.doi.org/10.1074/jbc.M004562200
- ↑ Odegard AL, Chandran K, Zhang X, Parker JS, Baker TS, Nibert ML. Putative autocleavage of outer capsid protein micro1, allowing release of myristoylated peptide micro1N during particle uncoating, is critical for cell entry by reovirus. J Virol. 2004 Aug;78(16):8732-45. PMID:15280481 doi:http://dx.doi.org/10.1128/JVI.78.16.8732-8745.2004
- ↑ Coffey CM, Sheh A, Kim IS, Chandran K, Nibert ML, Parker JS. Reovirus outer capsid protein micro1 induces apoptosis and associates with lipid droplets, endoplasmic reticulum, and mitochondria. J Virol. 2006 Sep;80(17):8422-38. PMID:16912293 doi:http://dx.doi.org/80/17/8422
- ↑ Zhang L, Chandran K, Nibert ML, Harrison SC. Reovirus mu1 structural rearrangements that mediate membrane penetration. J Virol. 2006 Dec;80(24):12367-76. Epub 2006 Sep 27. PMID:17005655 doi:http://dx.doi.org/10.1128/JVI.01343-06
- ↑ Ivanovic T, Agosto MA, Zhang L, Chandran K, Harrison SC, Nibert ML. Peptides released from reovirus outer capsid form membrane pores that recruit virus particles. EMBO J. 2008 Apr 23;27(8):1289-98. Epub 2008 Mar 27. PMID:18369316 doi:http://dx.doi.org/emboj200860
- ↑ Liemann S, Chandran K, Baker TS, Nibert ML, Harrison SC. Structure of the reovirus membrane-penetration protein, Mu1, in a complex with is protector protein, Sigma3. Cell. 2002 Jan 25;108(2):283-95. PMID:11832217
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