Promotion of cellular migration and apoptosis resistance by a mouse eye-specific phosphatidylethanolamine-binding protein

Abstract

The phosphatidylethanolamine (PE)-binding protein (PEBP) family is an evolutionary conserved group of proteins found in various species with multiple functions. We identified human PE-binding protein 4 (hPEBP4), a novel member of the PEBP family, as an anti-apoptotic molecule. Here we describe the cloning and functional characterization of the mouse homolog of hPEBP4 (mouse PEBP4, mPEBP4). Full-length cDNA of mPEBP4 contains 1048 bp with an open reading frame (ORF) of 729 bp, which is predicted to encode a 242-aa protein. mPEBP4 contains a PE-binding domain, in this case between amino acids 106 and 213. mPEBP4 localizes primarily to endoplasmic reticulum/Golgi apparatus. Interestingly, RT-PCR and in situ hybridization analyses indicate that mPEBP4 is specifically expressed in mouse eye tissue. We demonstrate that mPEBP4 promotes cellular migration and invasion by inhibiting ERK1/2 and JNK activation and up-regulating the expression of COX-2. In addition, mPEBP4 overexpression inhibits Epirubicin-induced cellular apoptosis. Considering that mPEBP4 is specifically expressed in retinal ganglion cells, whether mPEBP4 is an important molecule involved in visual function needs to be further investigated.