Pigment epithelium-derived factor: Neurotrophic activity and identification as a member of the serine protease inhibitor gene family

F. R. Steele, G. J. Chader, L. V. Johnson, J. Tombran-Tink

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Cultured pigment epithelial cells of the fetal human retina secrete a protein, pigment epithelium-derived factor (PEDF), that induces a neuronal phenotype in cultured human retinoblastoma cells. Morphological changes include the induction of an extensive neurite meshwork and the establishment of corona-like cellular aggregates surrounding a central lumen. The differentiated cells also show increases in the expression of neuron-specific enolase and the 200-kDa neurofilament subunit. Amino acid and DNA sequence data demonstrate that PEDF belongs to the serine protease inhibitor (serpin) family. The PEDF gene contains a typical signal-peptide sequence, initiator methionine codon, and polyadenylylation signal and matches the size of other members of the serpin superfamily (e.g., α1-antitrypsin). It lacks homology, however, at the putative serpin reactive center. Thus, PEDF could exert a paracrine effect in the embryonic retina, influencing neuronal differentiation by a mechanism that does not involve classic inhibition of serine protease activity.

Original languageEnglish (US)
Pages (from-to)1526-1530
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number4
StatePublished - Mar 1 1993


All Science Journal Classification (ASJC) codes

  • General

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