LEPREL1, a novel ER and Golgi resident member of the Leprecan family.

We have identified a novel protein, Leprecan-like 1 (LEPREL1), with profound similarity to the Leprecan family of proteoglycans. The genomic organization of the Leprecan gene family was found to be highly conserved. Expression analysis shows that LEPREL1 is expressed in most tissues as a 3.4 kb transcript encoding an 80 kDa protein. A LEPREL1 specific antibody stains many cell types including adipocytes and neuroendocrine cells of the gastrointestinal epithelium. Muscle tissue contains a specific 6.5 kb transcript and a 200 kDa protein. The 3.4 kb LEPREL1 transcript encodes a 708 amino acid protein containing a signal sequence, four tetratricopeptide repeats (TPRs), a leucine zipper, a P-loop, a prolyl 4-hydroxylase alpha domain (P4Halpha), and a C-terminal KDEL ER-retention motif. LEPREL1 is localized to the ER and Golgi network and over-expressing it affects normal protein disulfide isomerase staining patterns in the ER.