title: Driving forces of proteasome-catalyzed peptide splicing in yeast and humans.
abstract: Proteasome-catalyzed peptide splicing (PCPS) represents an additional activity of mammalian 20S proteasomes recently identified in connection with antigen presentation. We show here that PCPS is not restricted to mammalians but that it is also a feature of yeast 20S proteasomes catalyzed by all three active site β subunits. No major differences in splicing efficiency exist between human 20S standard- and immuno-proteasome or yeast 20S proteasome. Using H(2)(18)O to monitor the splicing reaction we also demonstrate that PCPS occurs via direct transpeptidation that slightly favors the generation of peptides spliced in cis over peptides spliced in trans. Splicing efficiency itself is shown to be controlled by proteasomal cleavage site preference as well as by the sequence characteristics of the spliced peptides. By use of kinetic data and quantitative analyses of PCPS obtained by mass spectrometry we developed a structural model with two PCPS binding sites in the neighborhood of the active Thr1.
authors: Institut für Biochemie, Charité - Universitätsmedizin Berlin, Oudenarder Straβe 16, 13347 Berlin, Germany. michele.mishto@charite.de
authors: Michele
authors: M
authors: Mishto
authors: Andrean
authors: A
authors: Goede
authors: Kathrin Textoris
authors: KT
authors: Taube
authors: Christin
authors: C
authors: Keller
authors: Katharina
authors: K
authors: Janek
authors: Petra
authors: P
authors: Henklein
authors: Agathe
authors: A
authors: Niewienda
authors: Alexander
authors: A
authors: Kloss
authors: Sabrina
authors: S
authors: Gohlke
authors: Burkhardt
authors: B
authors: Dahlmann
authors: Cordula
authors: C
authors: Enenkel
authors: Peter Michael
authors: PM
authors: Kloetzel
mesh_terms: D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D055162:Biocatalysis; D002461:Cell Line, Transformed; D002853:Chromatography, Liquid; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D019154:Protein Splicing; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010455:Peptides; D046988:Proteasome Endopeptidase Complex