Driving forces of proteasome-catalyzed peptide splicing in yeast and humans.
Mol Cell Proteomics
; 11(10): 1008-23, 2012 Oct.
Article
em En
| MEDLINE
| ID: mdl-22822185
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 ß 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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
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Saccharomyces cerevisiae
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Linfócitos B
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Processamento de Proteína
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Complexo de Endopeptidases do Proteassoma
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article