Table 1.

Viral-mediated inhibition of protein kinase R (PKR) activity

	Virus(es)	Viral protein	Mode of PKR inhibition	References
ssRNA
Orthomyxoviridae	Influenza A Influenza B	NS1	Direct interaction/dsRNA-mediated interaction	[26, 45]
Coronaviridae	Infectious bronchitis virus	NSp2	Inhibition of phosphorylation	[21]
	hCoV-229a	NSp15	dsRNA sequestration	[22]
	MERS-CoV	NS4a	dsRNA sequestration	[23, 27]
Bunyaviridae	Rift Valley fever virus	NSs	Proteasome-mediated degradation	[28]
Filoviridae	Ebolavirus	VP35	Unknown/possible dsRNA sequestration	[29]
Retroviridae	HIV	Tat	Pseudosubstrate/direct interaction	[9]
		TAR RNA	Decoy dsRNA	[10]
Flaviviridae	Hepatitis C virus	NS5a	Blocking of dimerisation/direct interaction	[32]
		E2	Pseudosubstrate/direct interaction	[33]
Reoviridae	Reoviruses	σ3/σ4	dsRNA sequestration	[34]
dsRNA
Herpesviridae	Human cytomegalovirus	pTRS1/plRS1	Interaction and relocalisation/dsRNA sequestration	[35]
dsDNA
Herpesviridae	Herpes simplex virus	γ134.5 US11 US3/UL13	Dephosphorylation of eIF2α substrate dsRNA sequestration/direct interaction Inhibition of activation	[24, 36, 37]
	Kaposi’s sarcoma herpes virus	vlRF2	Direct interaction and inhibition of phosphorylation	[38]
		vlRF3 (LANA2]	Inhibition of PKR-induced apoptosis	[39]
	Epstein–Barr virus	EBER RNAs	Decoy dsRNA	[40]
		SM	dsRNA sequestration/direct interaction	[41]
Poxiviridae	Vaccinia virus	E3L Ip25/p20]	dsRNA sequestration/direct interaction	[42, 43]
		K3L	Pseudosubstrate/direct interaction	[44]
Adenoviridae	Adenovirus	VAI RNA	Decoy dsRNA/pseudoactivator	[40]

Summary table of viral-encoded proteins that mediate evasion of PKR-mediated innate immune response. Viruses are classified by family and type of genome. ss: single-stranded; ds: double-stranded; NSp: nonstructural protein; VP: viral protein; TAR: transactivation responsive; vIRF3: viral IRF3-like protein; EBER: Epstein–Barr virus encoded RNAs; VAI: adenovirus-associated RNA-I.