en.wikipedia.org/wiki/Andes_virus
3 corrections found
It enters cells by using β3-integrins as receptors.
For Andes virus, the established entry receptor is protocadherin-1 (PCDH1), not β3 integrin. β3 integrins were older proposed candidates, but primary and ICTV sources now identify PCDH1 as the receptor used by American orthohantaviruses such as ANDV.
Full reasoning
This sentence is outdated and misleading. Modern primary-source evidence identifies protocadherin-1 (PCDH1) as the key cell-entry receptor for Andes virus (ANDV) and other New World/American orthohantaviruses.
A 2018 Nature paper reported that PCDH1 is an essential determinant of entry and infection for both Andes virus (ANDV) and Sin Nombre virus (SNV), and that the viral glycoproteins directly recognize PCDH1 for entry. The same study also showed that genetic ablation of PCDH1 made hamsters highly resistant to lethal ANDV challenge.
The current ICTV genus report for Orthohantavirus is consistent with that result: in its lifecycle description, it states that after engaging a cellular receptor, "protocadherin 1 in the case of American orthohantaviruses" mediates entry. Andes virus is an American orthohantavirus.
Older literature did propose β3 integrins as receptor candidates or attachment factors, so this wording likely reflects superseded literature. But stating flatly that ANDV enters cells "by using β3-integrins as receptors" is not accurate given the later receptor-identification work and current ICTV description.
2 sources
- Protocadherin-1 is essential for cell entry by New World hantaviruses
Here we identify protocadherin-1 (PCDH1) as an essential determinant of entry and infection ... by two hantaviruses that cause HPS, Andes virus (ANDV) and Sin Nombre virus (SNV). In vitro, we show that the surface glycoproteins of ANDV and SNV ... exploit PCDH1 for entry.
- Genus: Orthohantavirus | ICTV
After engaging a cellular receptor, protocadherin 1 in the case of American orthohantaviruses, virion-membrane fusion results in ... release ... of the virion RNP complex into the cytoplasm.
The spike proteins extend about 10 nm out from the surface and are tetrameric, consisting of four copies each of Gn and Gc with helical symmetry, in which Gn forms the stalk of the spike and Gc the head.
This misdescribes hantavirus spike architecture. Structural sources describe square/tetrameric spikes with fourfold or local symmetry, not helical symmetry, and place Gn in the membrane-distal head region rather than as the stalk.
Full reasoning
This sentence conflicts with current structural descriptions of orthohantavirus surface spikes in two ways.
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The spikes are not described as having helical symmetry. The ICTV report describes orthohantavirus envelopes as having square-shaped spikes made of tetrameric Gn-Gc heterodimers that form a surface lattice with local symmetry. Structural papers likewise describe the hantaviral spike as a tetrameric (Gn-Gc)4 assembly.
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The sentence reverses the head/stalk arrangement of Gn and Gc. Structural studies place the Gn head domain (GnH) at the membrane-distal/head region of the spike, where it shields the fusion loops of Gc. In other words, Gn is part of the outer/head region, not simply the stalk with Gc forming the head.
So the article's wording is inaccurate both in calling the spike symmetry "helical" and in assigning Gn to the stalk and Gc to the head.
2 sources
- Genus: Orthohantavirus | ICTV
The virion envelope ... is decorated with square shaped spikes, consisting of tetrameric GN-GC heterodimers, which protrude 10 nM from the membrane forming a surface lattice of local symmetry.
- Mechanistic basis for potent neutralization of Sin Nombre hantavirus by a human monoclonal antibody
Previous integrative cryo-electron tomography ... revealed that the ultrastructure arrangement of the hantaviral (Gn−Gc)4 is well conserved and consists of a tetramer of Gn−Gc heterodimers. The GnH forms the most membrane-distal region of the spike and shields fusion loops located in domain II of the Gc.
Once the genome has been transcribed, RdRp snatches caps from host messenger RNA (mRNA) to create viral mRNA that is primed for translation by host ribosomes to produce viral proteins.
This gets the order of events wrong. In hantaviruses, cap snatching provides the capped primer used to initiate viral mRNA transcription; it is not a step that happens only after the genome has already been transcribed.
Full reasoning
The sentence reverses the role of cap snatching in hantavirus transcription.
For hantaviruses, the viral polymerase uses short capped fragments stolen from host mRNAs as primers for viral mRNA synthesis. In other words, cap snatching is part of initiating and generating viral mRNA, not a later step that occurs only after the genome has already been transcribed.
The ICTV family report states that hantavirus proteins are produced from capped viral mRNAs and that the 5′ cap structure is obtained via cap snatching from cellular mRNAs. The ICTV Orthohantavirus report further notes that the L protein mediates cap-snatching for viral mRNA capping and that during transcription, host-cell-derived capped primers are used. A PNAS paper on hantavirus cap snatching likewise states that these viruses initiate viral transcription through cap snatching and that the capped RNAs are used by the viral polymerase during transcription initiation.
So the problem is the article's sequence of events: cap snatching is not something RdRp does only after transcription to make an already-transcribed RNA translatable; it is part of how the viral mRNA is generated in the first place.
3 sources
- Family: Hantaviridae | ICTV
Proteins are produced from capped and non-polyadenylated mRNAs. The 5′-cap structure is obtained via cap-snatching from cellular mRNAs.
- Genus: Orthohantavirus | ICTV
Large protein (L) ... Mediates cap-snatching for viral mRNA capping ... During primary transcription ... host cell-derived capped primers (cap snatching).
- Storage of cellular 5′ mRNA caps in P bodies for viral cap-snatching
These viruses all initiate viral transcription through the process of 'cap-snatching' ... P bodies then serve as a pool of primers during the initiation of viral mRNA synthesis by the viral polymerase.