Stress-activated kinases regulate protein stability.
Proteasome inhibitors have been used to demonstrate that many proteins of the signal transduction pathways are regulated by degradation via the ubiquitin-proteasome pathway. The key question is what events target specific proteins for ubiquitination at one time and prevent ubiquitination at other times? In this review, we develop the notion that there is a direct relationship between the phosphorylation/dephosphorylation cascade of the signal transduction pathways and the targeting of the regulatory proteins for ubiquitination. We present examples where phosphorylation appears to alter the interaction between the targeting systems and the substrate by modifying the targeting system, the substrate, or both. These interacting systems are seen in the response of p53, c-jun and ATF-2 in cells subjected to stress or DNA damage and to the normal regulated response in a variety of pathways including the IkappaB-NFkappaB and JAK-STAT pathways. The interweaving of the two post-translational networks, phosphorylation and ubiquitination, provides a powerful insight into global regulatory control pathways.
Fuchs
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SY
The Ruttenberg Cancer Center, Mount Sinai Medical School, New York, New York 10029, USA.
Fried
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VA
Ronai
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D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3; D006801:Humans; D051550:I-kappa B Kinase; D048031:JNK Mitogen-Activated Protein Kinases; D053616:Janus Kinase 3; D020928:Mitogen-Activated Protein Kinases; D016328:NF-kappa B / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D050794:STAT1 Transcription Factor; D013312:Stress, Physiological; D015534:Trans-Activators / Q000378:metabolism; D051176:beta Catenin
C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D011506:Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D015534:Trans-Activators; D051176:beta Catenin; D011505:Protein-Tyrosine Kinases; C507933:JAK3 protein, human; D053616:Janus Kinase 3; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3