TY - JOUR
T1 - Activation of Caspase-6 Is Promoted by a Mutant Huntingtin Fragment and Blocked by an Allosteric Inhibitor Compound
AU - Ehrnhoefer, Dagmar E.
AU - Skotte, Niels H.
AU - Reinshagen, Jeanette
AU - Qiu, Xiaofan
AU - Windshuegel, Bjorn
AU - Jaishankar, Priyadarshini
AU - Ladha, Safia
AU - Petina, Olga
AU - Khankischpur, Mehdi
AU - Nguyen, Yen T. N.
AU - Caron, Nicholas S.
AU - Razeto, Adelia
AU - Zu Rheda, Matthias Meyer
AU - Deng, Yu
AU - Huynh, Khuong T.
AU - Wittig, Ilka
AU - Gribbon, Philip
AU - Renslo, Adam R.
AU - Geffken, Detlef
AU - Gul, Sheraz
AU - Hayden, Michael R.
PY - 2019/9/19
Y1 - 2019/9/19
N2 - Aberrant activation of caspase-6 (C6) in the absence of other hallmarks of apoptosis has been demonstrated in cells and tissues from patients with Huntington disease (HD) and animal models. C6 activity correlates with disease progression in patients with HD and the cleavage of mutant huntingtin (mHTT) protein is thought to strongly contribute to disease pathogenesis. Here we show that the mHTT1-586 fragment generated by C6 cleavage interacts with the zymogen form of the enzyme, stabilizing a conformation that contains an active site and is prone to full activation. This shift toward enhanced activity can be prevented by a small-molecule inhibitor that blocks the interaction between C6 and mHTT1-586. Molecular docking studies suggest that the inhibitor binds an allosteric site in the C6 zymogen. The interaction of mHTT1-586 with C6 may therefore promote a self-reinforcing, feedforward cycle of C6 zymogen activation and mHTT cleavage driving HD pathogenesis.
AB - Aberrant activation of caspase-6 (C6) in the absence of other hallmarks of apoptosis has been demonstrated in cells and tissues from patients with Huntington disease (HD) and animal models. C6 activity correlates with disease progression in patients with HD and the cleavage of mutant huntingtin (mHTT) protein is thought to strongly contribute to disease pathogenesis. Here we show that the mHTT1-586 fragment generated by C6 cleavage interacts with the zymogen form of the enzyme, stabilizing a conformation that contains an active site and is prone to full activation. This shift toward enhanced activity can be prevented by a small-molecule inhibitor that blocks the interaction between C6 and mHTT1-586. Molecular docking studies suggest that the inhibitor binds an allosteric site in the C6 zymogen. The interaction of mHTT1-586 with C6 may therefore promote a self-reinforcing, feedforward cycle of C6 zymogen activation and mHTT cleavage driving HD pathogenesis.
U2 - 10.1016/j.chembiol.2019.07.001
DO - 10.1016/j.chembiol.2019.07.001
M3 - Journal article
C2 - 31353319
SN - 2451-9448
VL - 26
SP - 1295-1305.e6
JO - Cell Chemical Biology
JF - Cell Chemical Biology
IS - 9
ER -