Sharpin Antibody #4444

Shank-associated RH domain-interacting protein (Sharpin), also known as SIPL1, is a highly conserved gene among many mammalian species and is ubiquitously expressed in various types of cells and tissues. Sharpin harbors multiple functional motifs including an amino terminal coiled-coil (CC) domain, which has been shown to mediate the interaction between Sharpin and the scaffold protein SHANK (1). The other two domains, ubiquitin-like domain (UBL) and NPL4 zinc finger domain (NZF), facilitate ubiquitin-mediated protein recognition and degradation (2). Recent studies have shown that both UBL and NZF domains are essential for Sharpin to exert its function in part through ubiquitin-mediated mechanisms (3-5). Although Sharpin was initially identified as a scaffold protein within the postsynaptic density of neurons (1), recent studies have identified Sharpin as a novel modulator of immune and inflammatory diseases. An emerging mechanistic model suggests that Sharpin functions as an important adaptor component of the Linear Ubiquitin Chain Assembly Complex (LUBAC) that modulates activation of the canonical NF-κB signaling pathway (3,4,6,7), thereby regulating cell survival and apoptosis, cytokine production, and lymphoid tissue development. Indeed, mice with spontaneous mutations in the Sharpin gene develop chronic proliferative dermatitis that is characterized by eosinophilic inflammation of the skin and dysregulated lymphoid tissue development (8).