Modified RING finger, HC subclass (C3HC3D-type), found in Roquin-2
Roquin-2, also known as membrane-associated nucleic acid-binding protein (MNAB), RING finger and CCCH-type zinc finger domain-containing protein 2 (RC3H2), or RING finger protein 164 (RNF164), is an E3 ubiquitin ligase that is localized to the cytoplasm and upon stress is concentrated in stress granules. It is required for reactive oxygen species (ROS)-induced ubiquitination and degradation of apoptosis signal-regulating kinase 1 (ASK1, also known as MAP3K5). Roquin-2 interacts with 3'UTR of tumor necrosis factor receptor superfamily member 4 (TNFRSF4) and tumor-necrosis factor-alpha (TNFalpha), and modulates immune responses. Moreover, Roquin-2 shares functions with its paralog Roquin-1 in the repression of mRNAs controlling T follicular helper cells and systemic inflammation. Roquin-2 contains an N-terminal modified C3HC3D-type RING-HC finger with a potential E3 ubiquitin-ligase function, a highly conserved ROQ domain required for RNA binding and localization to stress granules, a coiled-coil (CC1), and a CCCH-type zinc finger that is involved in RNA recognition.