Oligoadenylate Synthetase Pathway (OAS Pathway)

The oligoadenylate synthetase (OAS) pathway is a crucial component of the innate immune response against viral infections. It is activated by cytosolic double-stranded RNA (dsRNA), leading to the synthesis of 2′-5′-linked oligoadenylates (2-5As). These 2-5As activate RNase L, an endoribonuclease that degrades viral and cellular RNA, inhibiting viral replication and promoting apoptosis of infected cells. The pathway involves OAS family proteins (OAS1, OAS2, OAS3, and OASL), each with distinct dsRNA binding requirements. Type I interferons (IFNs) induce OAS gene expression, and the system acts synergistically with other interferon-stimulated gene products.

Other names

2-5A PathwayInterferon-induced antiviral pathway

Activation leads to the synthesis of 2'-5'-linked oligoadenylates (2-5As) that activate RNase L, leading to RNA degradation and apoptosis.