Format

Send to

Choose Destination
Nat Immunol. 2001 Jul;2(7):644-51.

ER aminopeptidases generate a unique pool of peptides for MHC class I molecules.

Author information

1
Division of Immunology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA.

Abstract

We define here the specificity and significance of proteases in the endoplasmic reticulum (ER) that generate peptides for presentation by major histocompatibility complex (MHC) class I molecules. We show that aminopeptidases efficiently trimmed all residues except proline that flank the NH2-termini of antigenic precursors in the ER and caused an accumulation of X-P-Xn peptides. An aminopeptidase inhibitor blocked peptide trimming in the ER and, consequently, the generation of peptide-loaded MHC molecules. Peptide trimming in the ER is therefore a key step in the MHC class I antigen-processing pathway and also explains the paradox of why many MHC class I molecules display peptides with the X-P-Xn motif despite the inability of the transporter associated with antigen processing to transport such peptides from the cytoplasm.

PMID:
11429550
DOI:
10.1038/89800
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center