Table 2.
Proteins reported to interact with viperin
| Protein | Role of protein | Effect of interaction on viperin | Effect of interaction on the target protein | References |
|---|---|---|---|---|
| Cellular proteins | ||||
| IRAK 1 | Protein kinase involved in immune signaling | Co-activator of ddhCTP synthesis | Promotes Lys-63–linked ubiquitination of IRAK1 | 51, 55, 88 |
| TRAF6 | Lys-63–linked E3 ubiquitin ligase, involved in immune signaling | Co-activator of ddhCTP synthesis | Activates TRAF6 toward ubiquitination of IRAK1 | 51, 55, 88 |
| HADHB | β-Subunit of mitochondrial trifunctional protein, | Activator of ddhCTP synthesis | Inhibits thiolase activity of HADHB; promotes degradation of HADHB | 49, 50, 89 |
| FPPS | catalyzes synthesis of farnesyl diphosphate, a precursor for sterols | None observed | Promotes intracellular degradation of FPPS | 11, 90 |
| GBF1 | Guanine nucleotide exchange factor involved in protein trafficking in the early secretory pathway | Not known | Inhibits the cellular function of GBF1, leading to the selective release of TBEV particles | 91 |
| MAVS | Downstream adaptor of the cytosolic RIG-I and MDA-5 receptors; induces the IFN-β expression | Not known | Suppresses MAVS-dependent IFN-β production. May act indirectly | 10, 27, 92 |
| Helicase MCM2 | DNA helicase | Not known | Promotes methionine oxidation of MCM2, enhancing protein stability | 81 |
| UBE4A | E3 ubiquitin ligase mediating Lys-48–linked polyubiquitination of proteins | Promotes polyubiquitination and degradation through proteasome-mediated pathway | Not known | 30 |
| Viral proteins | ||||
| NS5A | Important for formation of viral replication complex | HCV NS5A deactivates viperin to catalyze the conversion reaction of CTP to ddhCTP | Promotes degradation of NS5A through proteasome-mediated pathway | 12–14, 17, 61, 93 |
| NS3 | Acts as protease/helicase in viral replication | Not known | Promotes proteasome-mediated degradation of NS3 in some viruses | 16–18, 93 |
| pp28 and pp65 (HCMV) | Tegument proteins involved in immune evasion or viral assembly and egress | Not known | Not known | 7, 94 |
| vMIA | Suppresses apoptosis by blocking permeabilization of the mitochondrial outer membrane | Relocalizes viperin from ER to mitochondria | Not known | 49, 95 |
| Glycoprotein B/D | Binds to membrane receptor on host cells facilitating viral entry | Disrupts interaction between viperin and TRAF6 in Herpesvirus infection | Direct modification of the proteins was not observed | 6, 7, 51 |
| C or N capsid proteins | Protects viral nucleic acids from host cell enzymes | Not known | May impair viral replication by interacting with capsid proteins | 16, 36, 40, 91 |