Manipulating JNK signaling with (--)-zuonin A.
Recently, in a virtual screening strategy to identify new compounds targeting the D-recruitment site (DRS) of the c-Jun N-terminal kinases (JNKs), we identified the natural product (-)-zuonin A. Here we report the asymmetric synthesis of (-)-zuonin A and its enantiomer (+)-zuonin A. A kinetic analysis for the inhibition of c-Jun phosphorylation by (-)-zuonin A revealed a mechanism of partial competitive inhibition. Its binding is proposed to weaken the interaction of c-Jun to JNK by approximately 5-fold, without affecting the efficiency of phosphorylation within the complex. (-)-Zuonin A inhibits the ability of both MKK4 and MKK7 to phosphorylate and activate JNK. The binding site of (-)-zuonin A is predicted by docking and molecular dynamics simulation to be located in the DRS of JNK. (+)-Zuonin A also binds JNK but barely impedes the binding of c-Jun. (-)-Zuonin A inhibits the activation of JNK, as well as the phosphorylation of c-Jun in anisomycin-treated HEK293 cells, with the inhibition of JNK activation being more pronounced. (-)-Zuonin A also inhibits events associated with constitutive JNK2 activity, including c-Jun phosphorylation, basal Akt activation, and MDA-MB-231 cell migration. Mutations in the predicted binding site for (-)-zuonin A can render it significantly more or less sensitive to inhibition than wild type JNK2, allowing for the design of potential chemical genetic experiments. These studies suggest that the biological activity reported for other lignans, such as saucerneol F and zuonin B, may be the result of their ability to impede protein-protein interactions within MAPK cascades.
Division of Medicinal Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States.
Tamer S
TS
Kaoud
Heekwang
H
Park
Shreya
S
Mitra
Chunli
C
Yan
Chun-Chia
CC
Tseng
Yue
Y
Shi
Jiney
J
Jose
Juliana M
JM
Taliaferro
Kiyoun
K
Lee
Pengyu
P
Ren
Jiyong
J
Hong
Kevin N
KN
Dalby
D030022:Aristolochia / Q000737:chemistry; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D029780:Chamaecyparis / Q000737:chemistry; D004789:Enzyme Activation / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D017705:Lignans / Q000138:chemical synthesis* / Q000494:pharmacology*; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048688:MAP Kinase Kinase 7 / Q000037:antagonists & inhibitors / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D048055:Mitogen-Activated Protein Kinase 8 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048056:Mitogen-Activated Protein Kinase 9 / Q000037:antagonists & inhibitors / Q000378:metabolism; D008958:Models, Molecular; D031701:Piper / Q000737:chemistry; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D032134:Saururaceae / Q000737:chemistry
D017705:Lignans; C579789:zuonin A; D048056:Mitogen-Activated Protein Kinase 9; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D048055:Mitogen-Activated Protein Kinase 8; D048670:MAP Kinase Kinase 4; D048688:MAP Kinase Kinase 7