Related Experiment Video
Updated: May 17, 2026

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.
Published on: September 1, 2015
Interferon-induced SCYL2 limits release of HIV-1 by triggering PP2A-mediated dephosphorylation of the viral protein
Kei Miyakawa1, Tatsuya Sawasaki, Satoko Matsunaga
1Department of Microbiology, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan.
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 Ser(52) and Ser(56) 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 Ser(52) and Ser(56) 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.
Related Concept Videos
Inhibitors of Viral Protein Synthesis
Leaky Scanning
Immune Response Against Viral Pathogens
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
Viruses with RNA Genomes
siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
Size and Structure of Viral Genomes

