Intracellular localization of the SARS coronavirus protein 9b: Evidence of active export from the nucleus

Moshynskyy, Igor; Viswanathan, Sathiyanarayanan; Vasilenko, Natalia; Lobanov, Vladislav A.; Petric, Martin; Babiuk, Lorne A.; Zakhartchouk, Alexander N.

doi:10.1016/j.virusres.2007.03.011

Cited by 22 publications

(30 citation statements)

References 23 publications

(20 reference statements)

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“…5, mask), which indicates that the two proteins are less than about 200 nm apart, reinforcing the notion that proteins 6 and 9b may interact in vivo. The expression of protein 9b in SARS-CoV infected cells was observed partially localized both in the cytoplasm and in the nucleus, in agreement with the described subcellular localization of recombinant 9b protein in transfected cells (Moshynskyy et al, 2007;von Brunn et al, 2007) and in SARS-CoV infected cells at similar hpi (Sharma et al, 2011) (Fig. 5, merge).…”

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confidence: 89%

Severe acute respiratory syndrome coronavirus accessory proteins 6 and 9b interact in vivo

et al. 2012

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The 3'proximal one-third of the severe acute respiratory syndrome coronavirus (SARS-CoV) genome encodes the structural proteins and eight accessory proteins, including 3a, 3b, 6, 7a, 7b, 8a, 8b and 9b, varying in length from 39 to 274aa which do not share significant homology with viral proteins of known coronaviruses. The SARS-CoV protein 6 is 63 amino acids in length and has been previously involved in virus pathogenicity and replication. To further analyze this functions, the interaction of SARS-CoV protein 6 with other viral and/or cellular factors has been analyzed during SARS-CoV infective cycle. Protein 6 immunoprecipitation from extracts of SARS-CoV infected cells and mass spectrometry analysis revealed an interaction of viral proteins 6 and 9b in biologically relevant conditions. This interaction has been reinforced by co-localization of both proteins in the cytoplasm of SARS-CoV infected cells.

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confidence: 89%

Severe acute respiratory syndrome coronavirus accessory proteins 6 and 9b interact in vivo

et al. 2012

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“…Protein 9b contains no known NLS and enters the nucleus by passive diffusion (Sharma et al, 2011). However, amino-acid residues 46 to 54 (LRLGSQLSL) of p9b belong to a nuclear export signal (NES) motif LX 1-3 LX 2-4 LXL known to be transported by exportin 1 via an energy-dependent mechanism (Moshynskyy et al, 2007). Indeed, SARS-CoV p9b has been shown to physically interact with exportin 1 and moreover, mutation of the leucine-rich NES or inhibition of exportin 1 by leptomycin B have been shown to inhibit nuclear export of the 9b protein (Sharma et al, 2011;Moshynskyy et al, 2007).…”

Section: Sars-cov P8a P8b and P8abmentioning

confidence: 99%

“…However, amino-acid residues 46 to 54 (LRLGSQLSL) of p9b belong to a nuclear export signal (NES) motif LX 1-3 LX 2-4 LXL known to be transported by exportin 1 via an energy-dependent mechanism (Moshynskyy et al, 2007). Indeed, SARS-CoV p9b has been shown to physically interact with exportin 1 and moreover, mutation of the leucine-rich NES or inhibition of exportin 1 by leptomycin B have been shown to inhibit nuclear export of the 9b protein (Sharma et al, 2011;Moshynskyy et al, 2007). The nuclear export of p9b facilitates its degradation in the cytoplasm, whereas accumulation of p9b in the nucleus can induce caspase-dependent apoptosis (Sharma et al, 2011).…”

Section: Sars-cov P8a P8b and P8abmentioning

confidence: 99%

Accessory proteins of SARS-CoV and other coronaviruses

et al. 2014

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The huge RNA genome of SARS coronavirus comprises a number of open reading frames that code for a total of eight accessory proteins. Although none of these are essential for virus replication, some appear to have a role in virus pathogenesis. Notably, some SARS-CoV accessory proteins have been shown to modulate the interferon signaling pathways and the production of pro-inflammatory cytokines. The structural information on these proteins is also limited, with only two (p7a and p9b) having their structures determined by X-ray crystallography. This review makes an attempt to summarize the published knowledge on SARS-CoV accessory proteins, with an emphasis on their involvement in virus-host interaction. The accessory proteins of other coronaviruses are also briefly discussed. This paper forms part of a series of invited articles in Antiviral Research on "From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses" (see Introduction by Hilgenfeld and Peiris (2013)).

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“…Although the protein initially accumulates in the nucleolus [64], it subsequently translocates to the outer membrane of mitochondria [63,65]. Nuclear export of other accessory proteins, namely SARS-CoV ORF9b, has also been previously reported [66] but how this spatio-temporal distribution impacts on ORF3b behavior and function is still unclear [67]. In fact, one study has reported that ORF3b is localized primarily in the nucleus with no evidence of mitochondrial localization [68].…”

Section: Sars Accessory Proteinsmentioning

confidence: 99%

“…Both anti-9b antibody and ORF9b antigen have been detected in clinical samples from SARS patients [37,59], with the latter also detected in virus infected cells [37]. Analysis, using fluorescence microscopy of live transfected cells and indirect immunofluorescence of transfected fixed cells, shows that ORF9b is exported outside of the cell nucleus and localizes to the endoplasmic reticulum [66,122]; the authors suggest that the 46-LRLGSQLSL-54 amino acid sequence motif of ORF9b functions as a nuclear export signal (NES) [66]. More recently, it was confirmed that ORF9b interacts with the cellular protein Crm1 and gets exported out of the nucleus using an active NES; this nucleocytoplasmic export of ORF9b is linked to apoptosis [123].…”

Section: Sars Accessory Proteinsmentioning

confidence: 99%

The Role of Severe Acute Respiratory Syndrome (SARS)-Coronavirus Accessory Proteins in Virus Pathogenesis

McBride

Fielding

2012

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A respiratory disease caused by a novel coronavirus, termed the severe acute respiratory syndrome coronavirus (SARS-CoV), was first reported in China in late 2002. The subsequent efficient human-to-human transmission of this virus eventually affected more than 30 countries worldwide, resulting in a mortality rate of ~10% of infected individuals. The spread of the virus was ultimately controlled by isolation of infected individuals and there has been no infections reported since April 2004. However, the natural reservoir of the virus was never identified and it is not known if this virus will re-emerge and, therefore, research on this virus continues. The SARS-CoV genome is about 30 kb in length and is predicted to contain 14 functional open reading frames (ORFs). The genome encodes for proteins that are homologous to known coronavirus proteins, such as the replicase proteins (ORFs 1a and 1b) and the four major structural proteins: nucleocapsid (N), spike (S), membrane (M) and envelope (E). SARS-CoV also encodes for eight unique proteins, called accessory proteins, with no known homologues. This review will summarize the current knowledge on SARS-CoV accessory proteins and will include: (i) expression and processing; (ii) the effects on cellular processes; and (iii) functional studies.

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Intracellular localization of the SARS coronavirus protein 9b: Evidence of active export from the nucleus

Cited by 22 publications

References 23 publications

Severe acute respiratory syndrome coronavirus accessory proteins 6 and 9b interact in vivo

Severe acute respiratory syndrome coronavirus accessory proteins 6 and 9b interact in vivo

Accessory proteins of SARS-CoV and other coronaviruses

The Role of Severe Acute Respiratory Syndrome (SARS)-Coronavirus Accessory Proteins in Virus Pathogenesis

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