Sci. Signal., 9 October 2012
Belt and Braces Antiviral ApproachIn the ongoing arms race between pathogens and their hosts, each side generates factors with which to thwart the other. In the case of HIV-1 infection, cells produce type I interferon (IFN), which induces production of tetherin (also known as BST2), which traps new virus particles at the plasma membrane, preventing their release. For its part, HIV-1 produces the protein Vpu, which causes the degradation of tetherin, thus promoting viral release. Miyakawa et al. found that another IFN-inducible host protein, SCYL2, antagonized the function of Vpu, enabling tetherin to fulfill its role as a viral restriction factor. Vpu requires phosphorylation at two serine residues to function normally, and SCYL2 recruited the phosphatase PP2A to Vpu to render it inactive. Together, these data suggest the existence of a host back-up system to restrict viral spreading.
Citation: K. Miyakawa, T. Sawasaki, S. Matsunaga, A. Tokarev, G. Quinn, H. Kimura, M. Nomaguchi, A. Adachi, N. Yamamoto, J. Guatelli, A. Ryo, Interferon-Induced SCYL2 Limits Release of HIV-1 by Triggering PP2A-Mediated Dephosphorylation of the Viral Protein Vpu. Sci. Signal. 5, ra73 (2012).
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