#11508 NTR: Selective viral autophagy (virophagy) promotes survival of virus infected cells

[Paul Denny]

According to PMID:
22020285
20159618
Selective autophagy of viruses (virophagy) promotes the survival of virus-infected cells
So, I think we need this term as a child to autophagy.

I would use this term to annotate a large number of proteins (about 100) in
PMID:22020285
and I am sure that it would be used elsewhere.

[RFoulger]

Perhaps something like:

name: viral autophagy ; GO:NEW
exact synonym: virophagy [PMID:22020285]
exact synonym: selective autophagic targeting of viral nucleocapsid [PMID:22020285]
broad synonym: xenophagy [PMID:18059171, PMID:23391695]
def: A selective form of autophagy in which cells digest viral components or virions.
Definition Xref: PMID:22020285, PMID:20159618, GOC:pad, GOC:bf, GOC:PARL
is_a: autophagy ; GO:0006914
is_a: defense response to virus ; GO:0051607

For the autophagy parentage to work, it would require the definition of ‘autophagy ; GO:0006914’ to be updated to take into account digesting non-self intracellular components.
E.g. change from:
The process in which cells digest parts of their own cytoplasm; allows for both recycling of macromolecular constituents under conditions of cellular stress and remodeling the intracellular structure for cell differentiation.
to:
The process in which cells digest cytoplasmic components; allows for both recycling of macromolecular constituents under conditions of cellular stress and remodeling the intracellular structure for cell differentiation. Includes digestion of the cell's own cytoplasm and digestion of intracellular pathogens. [PMID:20965422, PMID:23222486]

[Paul Denny]

Hi David
any news?
Cheers,
Paul

[David Osumi-Sutherland]

"For the autophagy parentage to work, it would require the definition of ‘autophagy ; GO:0006914’ to be updated to take into account digesting non-self intracellular components."

The 'auto' in 'autophagy' = self. So, I don't see how we could change the meaning to cover non-self or make a term for digestion of viral components a subclass of autophagy.

Happy to add a term for digestion of viral components by cells. And from a quick look through references, I can see that we may need to connect this to at least some elements of the pathways used for autophagy. Virophagy sounds like a reasonable name but checking google and pubmed suggests it is not commonly used. Any suggestions?

[David Osumi-Sutherland]

xenophagy ?

[David Osumi-Sutherland]

Perhaps also need a more general phagy term?

[Paul Denny]

I see what you mean about auto=self and so virophagy doesn't really fit. I don't think xenophagy would fit, either.

Agree that virophagy not a common term, so perhaps simply ignore and I should stick with GO:0002230 positive regulation of defense response to virus by host

[David Osumi-Sutherland]

Xenophagy is sometimes used. Looks like autophagy-like pathways implicated. See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131688/. 'positive regulation of defense response to virus by host' seems a bit weak - at least on its own - and misses important detail.

[David Osumi-Sutherland]

New term:

label "xenophagy"
definition: "The enclosure of a region of cytoplams containing an intracellular pathogen or some part of intracellular pathogens (e.g viral capsid) in a double membrane bound autophagosome, which then fuses with the lysosome leading to degregation of the contents."
comment: "While making xenophagy a subclass of (macro)autophagy may seem to directly contradict the definition of autophagy (literally self eating), it is clear that the same pathway is involved as in macroautophagy that doesn't target foreign material: formation of double-membrane-bounded autophagosomes that enclose a region of cytoplasm for degradation."
is_a: macroautophagy

Also added this comment to macroautophagy:
"Targetted macroautophagy sometimes targets regions of cytoplasm containing non-self, such as virus particles or components (e.g. see PMID:20159618). As this is essentially the same process as macroautophagy that encloses and digests only self, the term autophagy is still used despite the enclosure of some non-self (non-auto) entities."