Bcl-2 targets protein phosphatase 1 alpha to Bad.
The diverse forms of protein phosphatase 1 (PP1) in vivo result from the association of the catalytic subunit with different regulatory subunits. We recently have described that PP1alpha is a Ras-activated Bad phosphatase that regulates IL-2 deprivation-induced apoptosis. With the yeast two-hybrid system, GST fusion proteins, indirect immunofluorescence, and coimmunoprecipitation, we found that Bcl-2 interacts with PP1alpha and Bad. In contrast, Bad did not interact with 14-3-3 protein. Bcl-2 depletion decreased phosphatase activity and association of PP1alpha to Bad. Bcl-2 contains the RIVAF motif, analogous to the well characterized R/KXV/IXF consensus motif shared by most PP1-interacting proteins. This sequence is involved in the binding of Bcl-2 to PP1alpha. Disruption of Bcl-2/PP1alpha association strongly decreased Bcl-2 and Bad-associated phosphatase activity and formation of the trimolecular complex. These results suggest that Bcl-2 targets PP1alpha to Bad.
Ayllón
V
V
Department of Immunology and Oncology, Centro Nacional de Biotecnología, Campus de Cantoblanco, Madrid, Spain.
Cayla
X
X
García
A
A
Roncal
F
F
Fernández
R
R
Albar
J P
JP
Martínez
C
C
Rebollo
A
A
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000276:immunology; D001667:Binding, Competitive / Q000235:genetics / Q000276:immunology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D054645:Protein Phosphatase 1; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013601:T-Lymphocytes / Q000166:cytology / Q000201:enzymology; D020798:Two-Hybrid System Techniques; D051025:bcl-Associated Death Protein
C494820:Bad protein, mouse; D002352:Carrier Proteins; D046911:Macromolecular Substances; D019253:Proto-Oncogene Proteins c-bcl-2; D051025:bcl-Associated Death Protein; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1