tetano
Editor, Senior Moderator
J Mol Biol. 2013 Dec 28. pii: S0022-2836(13)00810-3. doi: 10.1016/j.jmb.2013.12.023. [Epub ahead of print]
Modulation of an ectodomain motif in the influenza A virus neuraminidase alters tetherin sensitivity and results in virus attenuation in vivo.
Grado VH1, Hai R1, Fernandes F2, Villanueva AB1, Carter C2, Yondola MA3.
Author information
Abstract
We previously demonstrated that ectodomain residue Asp286 in N2 neuraminidase (NA; Asp268 in N1 NA) present in budding-capable NA proteins contributes to productive NA plasma membrane transport partly by mediating escape from tetherin restriction1. Budding-incapable NA proteins contain a G at this position and either co-expression of HIV-1 vpu, or siRNA-mediated depletion of tetherin rescued budding capabilities in these proteins1. Furthermore, replacement of D286 with G in budding-capable NA proteins caused loss of function, preventing release of NA virus-like particles (VLPs). Here, we show that mutation of this residue specifically modulates the ability of NA to escape tetherin restriction at the plasma membrane and results in virus attenuation in vivo. Based on immunogold electron microscopy and co-immunoprecipitation assays, both NAD286-containing and NAD286G-containing proteins associated with tetherin in the ER. However, the NAD286G loss-of-function mutant also associated with the host factor outside the ER and in plasma membrane-localized VLPs as visualized using immunogold electron microscopy. We conclude that the presence of aspartate at residue 286 liberates NA from tetherin-dependent restriction upon exit from the ER compartment thus preventing restriction at the plasma membrane. Underscoring the importance of these observations, knockdown of tetherin resulted in a 1-1.5 log increase in influenza virus growth. Additionally, the loss-of-function mutation conferred attenuation in a mouse model of influenza infection as evidenced by a 5-fold increase in LD50 and increases in either percent survival or time to death dependent on the administered dose in vivo.
Copyright ? 2013. Published by Elsevier Ltd.
KEYWORDS:
budding, ectodomain, influenza, neuraminidase, tetherin
PMID:
24380762
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24380762
Modulation of an ectodomain motif in the influenza A virus neuraminidase alters tetherin sensitivity and results in virus attenuation in vivo.
Grado VH1, Hai R1, Fernandes F2, Villanueva AB1, Carter C2, Yondola MA3.
Author information
Abstract
We previously demonstrated that ectodomain residue Asp286 in N2 neuraminidase (NA; Asp268 in N1 NA) present in budding-capable NA proteins contributes to productive NA plasma membrane transport partly by mediating escape from tetherin restriction1. Budding-incapable NA proteins contain a G at this position and either co-expression of HIV-1 vpu, or siRNA-mediated depletion of tetherin rescued budding capabilities in these proteins1. Furthermore, replacement of D286 with G in budding-capable NA proteins caused loss of function, preventing release of NA virus-like particles (VLPs). Here, we show that mutation of this residue specifically modulates the ability of NA to escape tetherin restriction at the plasma membrane and results in virus attenuation in vivo. Based on immunogold electron microscopy and co-immunoprecipitation assays, both NAD286-containing and NAD286G-containing proteins associated with tetherin in the ER. However, the NAD286G loss-of-function mutant also associated with the host factor outside the ER and in plasma membrane-localized VLPs as visualized using immunogold electron microscopy. We conclude that the presence of aspartate at residue 286 liberates NA from tetherin-dependent restriction upon exit from the ER compartment thus preventing restriction at the plasma membrane. Underscoring the importance of these observations, knockdown of tetherin resulted in a 1-1.5 log increase in influenza virus growth. Additionally, the loss-of-function mutation conferred attenuation in a mouse model of influenza infection as evidenced by a 5-fold increase in LD50 and increases in either percent survival or time to death dependent on the administered dose in vivo.
Copyright ? 2013. Published by Elsevier Ltd.
KEYWORDS:
budding, ectodomain, influenza, neuraminidase, tetherin
PMID:
24380762
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24380762