Regulation of PIDD auto-proteolysis and activity by the molecular chaperone Hsp90.
In response to DNA damage, p53-induced protein with a death domain (PIDD) forms a complex called the PIDDosome, which either consists of PIDD, RIP-associated protein with a death domain and caspase-2, forming a platform for the activation of caspase-2, or contains PIDD, RIP1 and NEMO, important for NF-κB activation. PIDDosome activation is dependent on auto-processing of PIDD at two different sites, generating the fragments PIDD-C and PIDD-CC. Despite constitutive cleavage, endogenous PIDD remains inactive. In this study, we screened for novel PIDD regulators and identified heat shock protein 90 (Hsp90) as a major effector in both PIDD protein maturation and activation. Hsp90, together with p23, binds PIDD and inhibition of Hsp90 activity with geldanamycin efficiently disrupts this association and impairs PIDD auto-processing. Consequently, both PIDD-mediated NF-κB and caspase-2 activation are abrogated. Interestingly, PIDDosome formation itself is associated with Hsp90 release. Characterisation of cytoplasmic and nuclear pools of PIDD showed that active PIDD accumulates in the nucleus and that only cytoplasmic PIDD is bound to Hsp90. Finally, heat shock induces Hsp90 release from PIDD and PIDD nuclear translocation. Thus, Hsp90 has a major role in controlling PIDD functional activity.
Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, Epalinges 1066, Switzerland.
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A
Tinel
M J
MJ
Eckert
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E
Logette
S
S
Lippens
S
S
Janssens
B
B
Jaccard
M
M
Quadroni
J
J
Tschopp
D016227:Benzoquinones / Q000494:pharmacology; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D053418:Death Domain Receptor Signaling Adaptor Proteins; D057809:HEK293 Cells; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006367:HeLa Cells; D018869:Heat-Shock Response / Q000187:drug effects; D006801:Humans; D047029:Lactams, Macrocyclic / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D016227:Benzoquinones; D002352:Carrier Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; C485896:PIDD1 protein, human; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex; C001277:geldanamycin