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Sci. Signal., 9 October 2012
Vol. 5, Issue 245, p. ra73
[DOI: 10.1126/scisignal.2003212]


Interferon-Induced SCYL2 Limits Release of HIV-1 by Triggering PP2A-Mediated Dephosphorylation of the Viral Protein Vpu

Kei Miyakawa1,2, Tatsuya Sawasaki3, Satoko Matsunaga1, Andrey Tokarev4, Gary Quinn1, Hirokazu Kimura5, Masako Nomaguchi6, Akio Adachi6, Naoki Yamamoto7, John Guatelli4,8, and Akihide Ryo1*

1 Department of Microbiology, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan.
2 Japanese Foundation for AIDS Prevention, Tokyo 101-0061, Japan.
3 Cell-Free Science and Technology Research Center, Ehime University, Ehime 790-8577, Japan.
4 Department of Medicine, University of California, La Jolla, CA 92093, USA.
5 Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo 208-0011, Japan.
6 Department of Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan.
7 Department of Microbiology, National University of Singapore, Singapore 117597, Singapore.
8 San Diego Veterans Affairs Healthcare System, San Diego, CA 92161, USA.

Abstract: Human cells respond to infection by retroviruses through the actions of proteins that inhibit the spread of viruses to other cells. One example is bone marrow stromal cell antigen 2 (BST2; also known as tetherin), which is an interferon (IFN)–inducible protein that restricts the release of progeny virions from infected cells. The HIV-1 accessory protein Vpu (viral protein U) causes degradation of BST2, and phosphorylation of Vpu at residues Ser52 and Ser56 is required for this function. We report that the host protein SCY1-like protein 2 (SCYL2) mediates the dephosphorylation of Vpu, antagonizing Vpu function and facilitating BST2-dependent restriction of HIV-1 release. SCYL2 reduced the number of virus particles released from cells infected with wild-type HIV-1, but not a strain lacking vpu, in a BST2-dependent manner. SCYL2 stimulated the dephosphorylation of Vpu on Ser52 and Ser56 by recruiting protein phosphatase 2A (PP2A) to Vpu. Conversely, depletion of SCYL2 resulted in enhanced phosphorylation of Vpu and increased viral particle release. Moreover, SCYL2 was produced in response to type I IFN and contributed to IFN-mediated viral restriction. Together, these results suggest that SCYL2 serves as a regulatory factor for Vpu, reducing the extent of Vpu phosphorylation and consequently enhancing BST2-mediated viral restriction.

* To whom correspondence should be addressed. E-mail: aryo{at}

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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