title: Definition of Proteasomal Peptide Splicing Rules for High-Efficiency Spliced Peptide Presentation by MHC Class I Molecules.
abstract: Peptide splicing, in which two distant parts of a protein are excised and then ligated to form a novel peptide, can generate unique MHC class I-restricted responses. Because these peptides are not genetically encoded and the rules behind proteasomal splicing are unknown, it is difficult to predict these spliced Ags. In the current study, small libraries of short peptides were used to identify amino acid sequences that affect the efficiency of this transpeptidation process. We observed that splicing does not occur at random, neither in terms of the amino acid sequences nor through random splicing of peptides from different sources. In contrast, splicing followed distinct rules that we deduced and validated both in vitro and in cells. Peptide ligation was quantified using a model peptide and demonstrated to occur with up to 30% ligation efficiency in vitro, provided that optimal structural requirements for ligation were met by both ligating partners. In addition, many splicing products could be formed from a single protein. Our splicing rules will facilitate prediction and detection of new spliced Ags to expand the peptidome presented by MHC class I Ags.
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
authors.forename: Celia R
authors.initials: CR
authors.lastname: Berkers
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
authors.forename: Annemieke
authors.initials: A
authors.lastname: de Jong
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
authors.forename: Karianne G
authors.initials: KG
authors.lastname: Schuurman
authors.affiliation: Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; and.
authors.forename: Carsten
authors.initials: C
authors.lastname: Linnemann
authors.affiliation: Institute for Translational Vaccinology, 3721 MA Bilthoven, the Netherlands.
authors.forename: Hugo D
authors.initials: HD
authors.lastname: Meiring
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
authors.forename: Lennert
authors.initials: L
authors.lastname: Janssen
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
authors.forename: Jacques J
authors.initials: JJ
authors.lastname: Neefjes
authors.affiliation: Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; and.
authors.forename: Ton N M
authors.initials: TN
authors.lastname: Schumacher
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
authors.forename: Boris
authors.initials: B
authors.lastname: Rodenko
authors.affiliation: Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; h.ovaa@nki.nl.
authors.forename: Huib
authors.initials: H
authors.lastname: Ovaa
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology*; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000276:immunology; D019154:Protein Splicing
chemical_list: D015395:Histocompatibility Antigens Class I; D010455:Peptides; D046988:Proteasome Endopeptidase Complex