Publication
Title
Proteome-wide substrate analysis indicates substrate exclusion as a mechanism to generate caspase-7 versus caspase-3 specificity
Author
Abstract
Caspase-3 and -7 are considered functionally redundant proteases with similar proteolytic specificities. We performed a proteome-wide screen on a mouse macrophage lysate using the N-terminal combined fractional diagonal chromatography technology and identified 46 shared, three caspase-3-specific, and six caspase-7-specific cleavage sites. Further analysis of these cleavage sites and substitution mutation experiments revealed that for certain cleavage sites a lysine at the P5 position contributes to the discrimination between caspase-7 and -3 specificity. One of the caspase-7-specific substrates, the 40 S ribosomal protein S18, was studied in detail. The RPS18-derived P6-P5' undecapeptide retained complete specificity for caspase-7. The corresponding P6-P1 hexapeptide still displayed caspase-7 preference but lost strict specificity, suggesting that P' residues are additionally required for caspase-7-specific cleavage. Analysis of truncated peptide mutants revealed that in the case of RPS18 the P4-P1 residues constitute the core cleavage site but that P6, P5, P2', and P3' residues critically contribute to caspase-7 specificity. Interestingly, specific cleavage by caspase-7 relies on excluding recognition by caspase-3 and not on increasing binding for caspase-7. Molecular & Cellular Proteomics 8:2700-2714, 2009.
Language
English
Source (journal)
Molecular and cellular proteomics. - Birmingham, Ala
Publication
Birmingham, Ala : 2009
ISSN
1535-9476
Volume/pages
8 :12 (2009) , p. 2700-2714
ISI
000272711800008
Full text (Publisher's DOI)
UAntwerpen
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 18.10.2018
Last edited 28.08.2021