Antagonism of p66shc by melanoma inhibitory activity.
The p66shc protein governs oxidant stress and mammalian lifespan. Here, we identify melanoma inhibitory activity (MIA), a protein secreted by melanoma cells, as a novel binding partner and antagonist of p66shc. The N-terminal collagen homology-2 (CH2) domain of p66shc binds to the Src Homology-3 (SH3)-like domain of MIA in vitro. In cells, ectopically expressed MIA and p66shc colocalize and co-precipitate. MIA also co-precipitates with the CH2 domain of p66shc in vivo. MIA expression in vivo suppresses p66shc-stimulated increase in endogenous hydrogen peroxide (H(2)O(2)), and inhibits basal and H(2)O(2)-induced phosphorylation of p66shc on serine 36 and H(2)O(2)-induced death. In human melanoma cells expressing MIA, endogenous MIA and p66shc co-precipitate. Downregulation of MIA in melanoma cells increases basal and ultraviolet radiation (UVR)-induced phosphorylation of p66shc on serine 36, augments endogenous H(2)O(2) levels, and increases their susceptibility to UVR-induced death. These findings show that MIA binds to p66shc, and suggest that this interaction antagonizes phosphorylation and function of p66shc.
Kasuno
K
K
Cardiovascular Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
Naqvi
A
A
Dericco
J
J
Yamamori
T
T
Santhanam
L
L
Mattagajasingh
I
I
Yang
S
S
Meyskens
F L
FL
Bosserhoff
A-K
AK
Irani
K
K
D048868:Adaptor Proteins, Signal Transducing / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D001665:Binding Sites; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation; D011485:Protein Binding; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
D048868:Adaptor Proteins, Signal Transducing; D016326:Extracellular Matrix Proteins; C090059:MIA protein, human; D009363:Neoplasm Proteins; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D006861:Hydrogen Peroxide