Deletion of a proline-rich region and a transmembrane domain in fatty acidamide hydrolase

Fatty acid amide hydrolase contains a proline-rich sequence matching a cons ensus sequence for SH3-binding domains as well as a transmembrane domain. I n this study, deletion mutants lacking the proline-rich region and the tran smembrane domain were generated. Transfection experiments demonstrated that the proline-rich deleted amidase was enzymatically inactive. While immunos taining of the wild-type was always punctate with strong perinuclear staini ng characteristic for endoplasmic reticulum, the staining of the mutant was diffuse and distributed throughout the cytoplasm and perinuclear region. T hese observations along with the loss of activity suggest that the proline- rich region may play a role in the subcellular localization and enzymatic f unction. The transmembrane domain-deleted mutant was indistinguishable from the wild-type enzyme. (C) 1999 Federation of European Biochemical Societie s.