ZC3HAV1
Domain
The N-terminal domain is sufficient to bind to viral RNAs and promote their degradation. The second and fourth zinc fingers are involved in binding to specific viral RNAs (PubMed:20451500). Contains a divergent PARP homology ADP-ribosyltransferase domain which lacks the structural requirements for NAD[+] binding (PubMed:25635049). It is therefore inactive (PubMed:25043379, PubMed:25635049).
Function
Antiviral protein which inhibits the replication of viruses by recruiting the cellular RNA degradation machineries to degrade the viral mRNAs. Binds to a ZAP-responsive element (ZRE) present in the target viral mRNA, recruits cellular poly(A)-specific ribonuclease PARN to remove the poly(A) tail, and the 3'-5' exoribonuclease complex exosome to degrade the RNA body from the 3'-end. It also recruits the decapping complex DCP1-DCP2 through RNA helicase p72 (DDX17) to remove the cap structure of the viral mRNA to initiate its degradation from the 5'-end. Its target viruses belong to families which include retroviridae: human immunodeficiency virus type 1 (HIV-1), moloney and murine leukemia virus (MoMLV) and xenotropic MuLV-related virus (XMRV), filoviridae: ebola virus (EBOV) and marburg virus (MARV), togaviridae: sindbis virus (SINV) and Ross river virus (RRV). Specifically targets the multiply spliced but not unspliced or singly spliced HIV-1 mRNAs for degradation. Isoform 1 is a more potent viral inhibitor than isoform 2. Isoform 2 acts as a positive regulator of RIGI signaling resulting in activation of the downstream effector IRF3 leading to the expression of type I IFNs and IFN stimulated genes (ISGs).
Post-translational modifications
Phosphorylation at Ser-275 is essential for sequential phosphorylation of Ser-271, Ser-267, Ser-263 and Ser-257 by GSK3-beta. Phosphorylation by GSK3-beta enhances its antiviral activity (By similarity).
Sequence Similarities
Belongs to the ARTD/PARP family.
Cellular localization
- Isoform 1
- Cytoplasm
- Nucleus
- Localizes in the cytoplasm at steady state, but shuttles between nucleus and cytoplasm in a XPO1-dependent manner.
- Isoform 2
- Cytoplasm
Alternative names
ZC3HDC2, PRO1677, ZC3HAV1, Zinc finger CCCH-type antiviral protein 1, ADP-ribosyltransferase diphtheria toxin-like 13, Inactive Poly [ADP-ribose] polymerase 13, Zinc finger CCCH domain-containing protein 2, Zinc finger antiviral protein, ARTD13, PARP13, ZAP