Oligoadenylate synthase-like (OASL) proteins: dual functions and associations with diseases

The study of antiviral pathways to reveal methods for the effective response and clearance of virus is closely related to understanding interferon (IFN) signaling and its downstream target genes, IFN-stimulated genes. One of the key antiviral factors induced by IFNs, 2′-5′ oligoadenylate synthase (OAS), is a well-known molecule that regulates the early phase of viral infection by degrading viral RNA in combination with RNase L, resulting in the inhibition of viral replication. In this review, we describe OAS family proteins from a different point of view from that of previous reviews. We discuss not only RNase L-dependent (canonical) and -independent (noncanonical) pathways but also the possibility of the OAS family members as biomarkers for various diseases and clues to non-immunological functions based on recent studies. In particular, we focus on OASL, a member of the OAS family that is relatively less well understood than the other members. We will explain its anti- and pro-viral dual roles as well as the diseases related to single-nucleotide polymorphisms in the corresponding gene. Immunology: A broader role for antiviral proteins Ongoing research into a family of antiviral proteins uncovers a broader range of immune and non-immune functions. The body typically responds to infection by producing oligoadenylate synthase-like (OAS) proteins, which promote the destruction of viral genetic material. Young-Joon Kim and colleagues at Korea's Yonsei University have reviewed the current literature to explore the roles of the different OAS family members. Certain OAS proteins may actually assist viral replication in some circumstances, and scientists have also uncovered evidence for OAS-mediated antiviral mechanisms that do not rely on destruction of genetic material. Abnormalities in OAS levels have also been observed in patients with autoimmune conditions such as lupus and multiple sclerosis, suggesting that these proteins might offer a useful diagnostic indicator. Finally, preliminary data suggest that OAS proteins may regulate cellular survival, and thereby affect the progression of cancer.