Umfang:
?
ISSN:
1937-9145
Inhalt:
Apoptosis in response to the ligand CD95L (also known as Fas ligand) is initiated by caspase-8, which is activated by dimerization and self-cleavage at death-inducing signaling complexes (DISCs). Previous work indicated that the degree of substrate cleavage by caspase-8 determines whether a cell dies or survives in response to a death stimulus. To determine how a death ligand stimulus is effectively translated into caspase-8 activity, we assessed this activity over time in single cells with compartmentalized probes that are cleaved by caspase-8 and used multiscale modeling to simultaneously describe single-cell and population data with an ensemble of single-cell models. We derived and experimentally validated a minimal model in which cleavage of caspase-8 in the enzymatic domain occurs in an interdimeric manner through interaction between DISCs, whereas prodomain cleavage sites are cleaved in an intradimeric manner within DISCs. Modeling indicated that sustained membrane-bound caspase-8 activity is followed by transient cytosolic activity, which can be interpreted as a molecular timer mechanism reflected by a limited lifetime of active caspase-8. The activation of caspase-8 by combined intra- and interdimeric cleavage ensures weak signaling at low concentrations of CD95L and strongly accelerated activation at higher ligand concentrations, thereby contributing to precise control of apoptosis. - Dual modes of activation of caspase-8 enable precise control of apoptosis. - Dual modes of activation of caspase-8 enable precise control of apoptosis.
Anmerkung:
Gesehen am 06.08.2020
In:
Science signaling, Washington, DC [u.a.] : Assoc., 2008, 7(2014,316) Artikel-Nummer ra23, 33 Seiten, 1937-9145
In:
volume:7
In:
year:2014
In:
number:316
In:
extent:?
Sprache:
Englisch
DOI:
10.1126/scisignal.2004738
URL:
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