Recombinant Mouse RELT/TNFRSF19L Fc Chimera Protein, CF

RELT (Receptor Expressed in Lymphoid Tissues) is a 46 kDa (predicted) type I transmembrane glycoprotein belonging to the tumor necrosis factor receptor superfamily and designated TNFRSF19‑like (TNFRSF19L) (1, 2). It is primarily expressed in hematopoietic tissues and peripheral blood leukocytes (2, 3). Mouse RELT cDNA encodes 436 amino acids (aa), including a 31 aa signal peptide, a 138 aa extracellular domain (ECD) containing a TNF receptor cysteine‑rich domain and a potential N‑linked glycosylation site, a 21 aa transmembrane domain, and a 246 aa cytoplasmic region that lacks a death domain (2). Within the ECD, mouse RELT shares 78%, 89%, 70%, 70% and 67% aa sequence homology with human, rat, canine, porcine and bovine RELT, respectively. Among TNFRSF members, the RELT extracellular domain is most closely related to that of TROY/TNFRSF19 and OX40 (2). Neither human nor mouse RELT bind any of the ~19 TNF superfamily ligands that have been tested (1). Two related transmembrane proteins, RELL1 and RELL2, have been identified in both human and mouse (3). RELL1 and 2 are coexpressed with and can interact with RELT, and are thought to modulate its signaling (3‑5). Intracellularly, RELT has been shown to bind the adaptor protein TRAF‑1 and activate the NF‑ kappaB pathway, the phospholipid scramblase PLSCR1, and the oxidative stress responsive protein OSR1 (2‑5). Another investigator notes association and signaling through SPAK, but not TRAF or NF kappaB (6). When overexpressed in HEK‑293 cells, RELT induces p38 and JNK signaling and activates apoptosis (4‑6).