RING finger, HC subclass, found in tripartite motif-containing protein TRIM2, TRIM3, and similar proteins
TRIM2, also known as RING finger protein 86 (RNF86), is an E3 ubiquitin-protein ligase that ubiquitinates the neurofilament light chain, a component of the intermediate filament in axons. Loss of function of TRIM2 results in early-onset axonal neuropathy. TRIM3, also known as brain-expressed RING finger protein (BERP), RING finger protein 97 (RNF97), or RING finger protein 22 (RNF22), is an E3 ubiquitin-protein ligase involved in the pathogenesis of various cancers. It also plays an important role in the central nervous system (CNS). In addition, TRIM3 may be involved in vesicular trafficking via its association with the cytoskeleton-associated-recycling or transport (CART) complex that is necessary for efficient transferrin receptor recycling, but not for epidermal growth factor receptor (EGFR) degradation. Both TRIM2 and TRIM3 belong to the C-VII subclass of TRIM (tripartite motif)-NHL family that is defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil domain, as well as a NHL (named after proteins NCL-1, HT2A and Lin-41 that contain repeats folded into a six-bladed beta propeller) repeat domain positioned C-terminal to the RBCC domain.