TY - JOUR
T1 - The copper chaperone CCS facilitates copper binding to MEK1/2 to promote kinase activation
AU - Grasso, Michael
AU - Bond, Gavin J.
AU - Kim, Ye Jin
AU - Boyd, Stefanie
AU - Dzebo, Maria Matson
AU - Valenzuela, Sebastian
AU - Tsang, Tiffany
AU - Schibrowsky, Natalie A.
AU - Alwan, Katherine B.
AU - Blackburn, Ninian J.
AU - Burslem, George M.
AU - Wittung-Stafshede, Pernilla
AU - Winkler, Duane D.
AU - Marmorstein, Ronen
AU - Brady, Donita C.
N1 - Publisher Copyright:
© 2021 THE AUTHORS.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Normal physiology relies on the precise coordination of intracellular signaling pathways that respond to nutrient availability to balance cell growth and cell death. The canonical mitogen-activated protein kinase pathway consists of the RAFMEK- ERK signaling cascade and represents one of the most well-defined axes within eukaryotic cells to promote cell proliferation, which underscores its frequent mutational activation in human cancers. Our recent studies illuminated a function for the redox-active micronutrient copper (Cu) as an intracellular mediator of signaling by connecting Cu to the amplitude of mitogen-activated protein kinase signaling via a direct interaction between Cu and the kinases MEK1 and MEK2. Given the large quantities of molecules such as glutathione and metallothionein that limit cellular toxicity from free Cu ions, evolutionarily conserved Cu chaperones facilitate efficient delivery of Cu to cuproenzymes. Thus, a dedicated cellular delivery mechanism of Cu to MEK1/2 likely exists. Using surface plasmon resonance and proximity-dependent biotin ligase studies, we report here that the Cu chaperone for superoxide dismutase (CCS) selectively bound to and facilitated Cu transfer to MEK1. Mutants of CCS that disrupt Cu(I) acquisition and exchange or a CCS small-molecule inhibitor were used and resulted in reduced Cu-stimulated MEK1 kinase activity. Our findings indicate that the Cu chaperone CCS provides fidelity within a complex biological system to achieve appropriate installation of Cu within the MEK1 kinase active site that in turn modulates kinase activity and supports the development of novel MEK1/2 inhibitors that target the Cu structural interface or blunt dedicated Cu delivery mechanisms via CCS.
AB - Normal physiology relies on the precise coordination of intracellular signaling pathways that respond to nutrient availability to balance cell growth and cell death. The canonical mitogen-activated protein kinase pathway consists of the RAFMEK- ERK signaling cascade and represents one of the most well-defined axes within eukaryotic cells to promote cell proliferation, which underscores its frequent mutational activation in human cancers. Our recent studies illuminated a function for the redox-active micronutrient copper (Cu) as an intracellular mediator of signaling by connecting Cu to the amplitude of mitogen-activated protein kinase signaling via a direct interaction between Cu and the kinases MEK1 and MEK2. Given the large quantities of molecules such as glutathione and metallothionein that limit cellular toxicity from free Cu ions, evolutionarily conserved Cu chaperones facilitate efficient delivery of Cu to cuproenzymes. Thus, a dedicated cellular delivery mechanism of Cu to MEK1/2 likely exists. Using surface plasmon resonance and proximity-dependent biotin ligase studies, we report here that the Cu chaperone for superoxide dismutase (CCS) selectively bound to and facilitated Cu transfer to MEK1. Mutants of CCS that disrupt Cu(I) acquisition and exchange or a CCS small-molecule inhibitor were used and resulted in reduced Cu-stimulated MEK1 kinase activity. Our findings indicate that the Cu chaperone CCS provides fidelity within a complex biological system to achieve appropriate installation of Cu within the MEK1 kinase active site that in turn modulates kinase activity and supports the development of novel MEK1/2 inhibitors that target the Cu structural interface or blunt dedicated Cu delivery mechanisms via CCS.
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U2 - 10.1016/j.jbc.2021.101314
DO - 10.1016/j.jbc.2021.101314
M3 - Article
C2 - 34715128
AN - SCOPUS:85120825900
SN - 0021-9258
VL - 297
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 6
M1 - 101314
ER -