Bcl-2 interacting protein, BAG-1, binds to and activates the kinase Raf-1.
The Bcl-2 protein blocks programmed cell death (apoptosis) through an unknown mechanism. Previously we identified a Bcl-2 interacting protein BAG-1 that enhances the anti-apoptotic effects of Bcl-2. Like BAG-1, the serine/threonine protein kinase Raf-1 also can functionally cooperate with Bcl-2 in suppressing apoptosis. Here we show that Raf-1 and BAG-1 specifically interact in vitro and in yeast two-hybrid assays. Raf-1 and BAG-1 can also be coimmunoprecipitated from mammalian cells and from insect cells infected with recombinant baculoviruses encoding these proteins. Furthermore, bacterially-produced BAG-1 protein can increase the kinase activity of Raf-1 in vitro. BAG-1 also activates this mammalian kinase in yeast. These observations suggest that the Bcl-2 binding protein BAG-1 joins Ras and 14-3-3 proteins as potential activators of the kinase Raf-1.
Wang
H G
HG
The Burnham Institute, La Jolla, CA 92037, USA.
Takayama
S
S
Rapp
U R
UR
Reed
J C
JC
D000818:Animals; D017209:Apoptosis; D002352:Carrier Proteins / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D004789:Enzyme Activation; D005982:Glutathione Transferase; D006801:Humans; D007700:Kinetics; D008322:Mammals; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2; D019908:Proto-Oncogene Proteins c-raf; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D018411:Spodoptera; D014157:Transcription Factors; D014162:Transfection
C091732:BCL2-associated athanogene 1 protein; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D005982:Glutathione Transferase; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf