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

Abstract

Fatty acid amide hydrolase contains a proline-rich sequence matching a consensus sequence for SH3-binding domains as well as a transmembrane domain. In this study, deletion mutants lacking the proline-rich region and the transmembrane domain were generated. Transfection experiments demonstrated that the proline-rich deleted amidase was enzymatically inactive. While immunostaining of the wild-type was always punctate with strong perinuclear staining characteristic for endoplasmic reticulum, the staining of the mutant was diffuse and distributed throughout the cytoplasm and perinuclear region. These observations along with the loss of activity suggest that the proline-rich region may play a role in the subcellular localization and enzymatic function. The transmembrane domain-deleted mutant was indistinguishable from the wild-type enzyme.