The ER aminopeptidase, ERAP1, trims precursors to lengths of MHC class I peptides by a "molecular ruler" mechanism.

ABSTRACT: Endoplasmic reticulum aminopeptidase 1 (ERAP1) is an IFN-gamma-induced aminopeptidase in the endoplasmic reticulum that trims longer precursors to the antigenic peptides presented on MHC class I molecules. We recently reported that purified ERAP1 trimmed N-extended precursors but spared peptides of 8-9 residues, the length required for binding to MHC class I molecules. Here, we show another remarkable property of ERAP1: that it strongly prefers substrates 9-16 residues long, the lengths of peptides transported efficiently into the ER by the transporter associated with antigen processing (TAP) transporter. This aminopeptidase rapidly degraded a model 13-mer to a 9-mer and then stopped, even though the substrate and the product had identical N- and C-terminal sequences. No other aminopeptida

SUBMITTER: Chang SC 

PROVIDER: S-EPMC1287962 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature