This domain, consisting of the distinct N-terminal PRY subdomain followed by the SPRY subdomain, is found at the C-terminus of the RING finger protein RNF135 (also known as Riplet/RNF135), which ubiquitinates RIG-I (retinoic acid-inducible gene-I) to promote interferon-beta induction during the early phase of viral infection. Normally, RIG-I is activated by TRIM25 in response to viral infection, leading to activation of the RIG-I signaling pathway, thus resulting in type I interferon production to limit viral replication. However, RNF135, consisting of an N-terminal RING finger domain, C-terminal SPRY and PRY motifs and showing sequence similarity to TRIM25, acts as an alternative factor that promotes RIG-I activation independent of TRIM25.
Jiyao W et al.(2023). "The conserved domain database in 2023.",