Molecular cloning, expression and characterization of human palmitoyl-protein thioesterase-2

Abigail A. Soyomho, Sandra L. Hofmann

Research output: Contribution to journalArticle

Abstract

The association of many signal transducing proteins with the plasma membrane often depends upon the dynamic covalent attachment of fatty acids like palmitate. We recently purified and cloned a iysosomal depalmitoylating enzyme, palmitoyl-protein thioesterase (PPT), from bovine brain using H-Ras as substrate. This enzyme was subsequently shown to be defective in the lysosomal storage disease, infantile neuronal ctroid lipofuscino&is. We hereby describe the cloning and expression of another depalmitoyiating enzyme, PPT2. which shares 18% overall identity with PPT1. at the protein level. Northern hybridization revealed a ubiquitous, but low level expression of a predominant 2.0 kb mRNA. The deduced amino acid sequence of PPT2 predicts a protein with 302 amino acids that includes a hydrophobic leader peptide and five potential glycosylation sites. When expressed in simian COS cells, human PPT2 cDNA directs the synthesis of a functional enzyme which is modified by asparagine-linked oligosaccharides and cosediments with lysosomal enzyme markers by Percoll gradient density fractionation. Preliminary experiments indicate, however, that the substrate specificity and tissue dist rib u t ion of PPT2 is different from that of the parent enzyme. PPT1.

Original languageEnglish (US)
JournalFASEB Journal
Volume11
Issue number9
Publication statusPublished - 1997

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ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Cell Biology

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