extracellular domain (ECD) found in the secreted Ly-6/uPAR-related protein 1 (SLURP-1)-like family
The SLURP-1-like family includes SLURP-1 and Ly6/PLAUR domain-containing protein 2 (LYPD2). SLURP-1 (also called ARS component B, or ARS (component B)-81/S, or anti-neoplastic urinary protein (ANUP)) has an antitumor activity. It was found to be a marker of late differentiation of the skin. It is implicated in maintaining the physiological and structural integrity of the keratinocyte layers of the skin. In vitro SLURP-1 down-regulates keratinocyte proliferation; the function may involve the proposed role as modulator of nicotinic acetylcholine receptors (nAChRs) activity. In vitro it inhibits alpha-7-dependent nAChR currents in an allosteric manner. In T cells SLURP-1 may be involved in regulation of intracellular Ca(2+) signaling. It may also have an immunomodulatory function in the cornea. The function may implicate a possible role as a scavenger receptor for PLAU thereby blocking PLAU-dependent functions of PLAUR such as in cell migration and proliferation. LYPD2 is a lymphocyte antigen-6 family protein and shows high sequence similarity with SLURP-1. Members in this family contain an extracellular domain (ECD) that belongs to Ly-6 antigen/uPA receptor-like (LU) superfamily and exhibits a snake toxin-like fold (also known as three-finger toxin/3FTx fold or three-fingered protein/TFP domain fold).