| Structural highlights
Function
[CPSF6_HUMAN] Component of the cleavage factor Im complex (CFIm) that plays a key role in pre-mRNA 3'-processing. Involved in association with NUDT21/CPSF5 in pre-MRNA 3'-end poly(A) site cleavage and poly(A) addition. CPSF6 binds to cleavage and polyadenylation RNA substrates and promotes RNA looping.[1] [2] [3] [4] [5]
Publication Abstract from PubMed
The HIV-1 genome enters cells inside a shell comprised of capsid (CA) protein. Variation in CA sequence alters HIV-1 infectivity and escape from host restriction factors. However, apart from the Cyclophilin A-binding loop, CA has no known interfaces with which to interact with cellular cofactors. Here we describe a novel protein-protein interface in the N-terminal domain of HIV-1 CA, determined by X-ray crystallography, which mediates both viral restriction and host cofactor dependence. The interface is highly conserved across lentiviruses and is accessible in the context of a hexameric lattice. Mutation of the interface prevents binding to and restriction by CPSF6-358, a truncated cytosolic form of the RNA processing factor, cleavage and polyadenylation specific factor 6 (CPSF6). Furthermore, mutations that prevent CPSF6 binding also relieve dependence on nuclear entry cofactors TNPO3 and RanBP2. These results suggest that the HIV-1 capsid mediates direct host cofactor interactions to facilitate viral infection.
CPSF6 Defines a Conserved Capsid Interface that Modulates HIV-1 Replication.,Price AJ, Fletcher AJ, Schaller T, Elliott T, Lee K, Kewalramani VN, Chin JW, Towers GJ, James LC PLoS Pathog. 2012 Aug;8(8):e1002896. Epub 2012 Aug 30. PMID:22956906[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Ruegsegger U, Blank D, Keller W. Human pre-mRNA cleavage factor Im is related to spliceosomal SR proteins and can be reconstituted in vitro from recombinant subunits. Mol Cell. 1998 Jan;1(2):243-53. PMID:9659921
- ↑ Ruegsegger U, Beyer K, Keller W. Purification and characterization of human cleavage factor Im involved in the 3' end processing of messenger RNA precursors. J Biol Chem. 1996 Mar 15;271(11):6107-13. PMID:8626397
- ↑ Brown KM, Gilmartin GM. A mechanism for the regulation of pre-mRNA 3' processing by human cleavage factor Im. Mol Cell. 2003 Dec;12(6):1467-76. PMID:14690600
- ↑ Kim S, Yamamoto J, Chen Y, Aida M, Wada T, Handa H, Yamaguchi Y. Evidence that cleavage factor Im is a heterotetrameric protein complex controlling alternative polyadenylation. Genes Cells. 2010 Sep 1;15(9):1003-13. doi: 10.1111/j.1365-2443.2010.01436.x., Epub 2010 Jul 29. PMID:20695905 doi:10.1111/j.1365-2443.2010.01436.x
- ↑ Yang Q, Coseno M, Gilmartin GM, Doublie S. Crystal Structure of a Human Cleavage Factor CFI(m)25/CFI(m)68/RNA Complex Provides an Insight into Poly(A) Site Recognition and RNA Looping. Structure. 2011 Feb 2. PMID:21295486 doi:10.1016/j.str.2010.12.021
- ↑ Price AJ, Fletcher AJ, Schaller T, Elliott T, Lee K, Kewalramani VN, Chin JW, Towers GJ, James LC. CPSF6 Defines a Conserved Capsid Interface that Modulates HIV-1 Replication. PLoS Pathog. 2012 Aug;8(8):e1002896. Epub 2012 Aug 30. PMID:22956906 doi:http://dx.doi.org/10.1371/journal.ppat.1002896
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