Proteasome-mediated degradation antagonizes critical levels of the apoptosis-inducing C1D protein.
The C1D gene is expressed in a broad spectrum of mammalian cells and tissues but its product induces apoptotic cell death when exceeding a critical level. Critical levels are achieved in a fraction of cells by transient transfection with EGFP-tagged C1D expression constructs. However, transfected cells expressing sub-critical levels of C1D(EGFP) escape apoptotic cell death by activation of a proteasome-mediated rescue mechanism. Inhibition of the proteasome-dependent degradation of the C1D(EGFP) protein results in a parallel increase of the intracellular C1D level and in the fraction of apoptotic cells.
Rothbarth
Karsten
K
Division Biochemistry of the Cell (B0300), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. werner@dkfz.de
Stammer
Hermann
H
Werner
Dieter
D