B-box-type 2 zinc finger found in tripartite motif-containing proteins, TRIM4, TRIM17, TRIM41, TRIM52 and similar proteins
This family includes a group of tripartite motif-containing proteins, including TRIM4, TRIM17, TRIM41 and TRIM52. TRIM4, also known as RING finger protein 87 (RNF87), is a cytoplasmic E3 ubiquitin-protein ligase that recently evolved and is present only in higher mammals. It transiently interacts with mitochondria, induces mitochondrial aggregation and sensitizes the cells to hydrogen peroxide (H2O2) induced death. Its interaction with peroxiredoxin 1 (PRX1) is critical for the regulation of H2O2 induced cell death. Moreover, TRIM4 functions as a positive regulator of RIG-I-mediated type I interferon induction. It regulates the K63-linked ubiquitination of RIG-1 and assembly of antiviral signaling complex at mitochondria. TRIM17, also known as RING finger protein 16 (RNF16) or testis RING finger protein (Terf), is a crucial E3 ubiquitin ligase that is necessary and sufficient for neuronal apoptosis and contributes to Mcl-1 ubiquitination in cerebellar granule neurons (CGNs). It interacts in a SUMO-dependent manner with nuclear factor of activated T cell NFATc3 transcription factor, and thus inhibits the activity of NFATc3 by preventing its nuclear localization. In contrast, it binds to and inhibits NFATc4 transcription factor in a SUMO-independent manner. Moreover, TRIM17 stimulates degradation of kinetochore protein ZW10 interacting protein (ZWINT), a known component of the kinetochore complex required for mitotic spindle checkpoint, and negatively regulates cell proliferation. TRIM41, also known as RING finger-interacting protein with C kinase (RINCK), is an E3 ubiquitin-protein ligase that promotes the ubiquitination of protein kinase C (PKC) isozymes in cells. It specifically recognizes the C1 domain of PKC isozymes. It controls the amplitude of PKC signaling by controlling the amount of PKC in the cell. TRIM52, also known as RING finger protein 102 (RNF102), is encoded by a novel, noncanonical antiviral TRIM52 gene in primate genomes with unique specificity determined by the rapidly evolving RING domain. TRIM4, TRIM17 and TRIM41 belong to the C-IV subclass of TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a RING finger, Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain. In contrast, TRIM52 lacks the putative viral recognition SPRY/B30.2 domain, and thus has been classified to the C-V subclass of TRIM family that contains only RBCC domains. The type 2 B-box (Bbox2) zinc finger is characterized by a CHC3H2 zinc-binding consensus motif.
Jiyao W et al.(2023). "The conserved domain database in 2023.",