Clotrimazole Inhibits the Ca2+-ATPase (SERCA) by Interfering with Ca2+ Binding and Favoring the E2 Conformation

Abstract

Clotrimazole (CLT) is an antimycotic imidazole derivative that is known to inhibit cytochrome P-450, ergosterol biosynthesis and proliferation of cells in culture, and to interfere with cellular Ca 2؉ homeostasis. We found that CLT inhibits the Ca 2؉ -ATPase of rabbit fast-twitch skeletal muscle (SERCA1), and we characterized in detail the effect of CLT on this calcium transport ATPase. We used biochemical methods for characterization of the ATPase and its partial reactions, and we also performed measurements of charge movements following adsorption of sarcoplasmic reticulum vesicles containing the ATPase onto a gold-supported biomimetic membrane. CLT

Tead1 is required for maintaining adult cardiomyocyte function, and its loss results in lethal dilated cardiomyopathy

“…SR-associated SERCA hydrolytic activity was determined by a colorimetric method (60,61). The reaction was carried in the assay buffer contained 40 mmol/l Tris, 80 mmol/l NaCl, 8 mmol/l MgAc 2 , 1 mmol/l EDTA, pH7.5.…”

Pre-steady State Electrogenic Events of Ca2+/H+ Exchange and Transport by the Ca2+-ATPase

“…We have described here pre-steady state charge movements induced by Ca 2ϩ concentration jumps in the absence of ATP or by ATP concentration jumps in the presence of Ca 2ϩ delivered to Ca 2ϩ -ATPase vesicles adsorbed onto an alkanethiol/phospholipid mixed bilayer anchored to a gold electrode (16). This technique has been used in studies of electrogenic transport by several membrane proteins (17)(18)(19)(20)(21)(22)(23). In our experiments, the detected charge movements are attributed to the binding of activating Ca 2ϩ to the Ca 2ϩ -ATPase in the absence of ATP and to translocation of bound Ca 2ϩ following the addition of ATP.…”

Clotrimazole, an antifungal drug possessing diverse actions, increases the vulnerability to cadmium in lymphocytes dissociated from rat thymus

“…1-3). Clotrimazole alone induces apoptosis (Ito et al, 2002), inhibits sarcoplasmic Ca 2+ -ATPase (Snajdrova et al, 1998;Bartolommei et al, 2006), and blocks Ca 2+ -activated K + channels (Brugnara et al, 1993;Rettenhouse et al, 1997;Welker and Drews, 1997;Wu et al, 1999). However, it is unlikely that the profound cytotoxic action is attributed to such actions of clotrimazole because of following results.…”

“…Clotrimazole, as an antifungal drug (Yoshida and Aoyama, 1987;Vanden Bossche et al, 1989), possesses diverse actions on cellular functions (Brugnara et al, 1993;Rettenhouse et al, 1997;Welker and Drews, 1997;Snajdrova et al, 1998;Wu et al, 1999;Ito et al, 2002;Isaev et al, 2002;Bartolommei et al, 2006;Usul et al, 2006). Clotrimazole also protects the cells treated with A23187, a calcium ionophore, inducing an overload of intracellular Ca 2+ resulting in the cell death in a Ca 2+ -dependent manner (Horimoto et al, 2006, also Fig.…”

“…Clotrimazole inhibits Ca 2+ -ATPase and releases Ca 2+ from endoplasmic reticulum (Snajdrova et al, 1998;Bartolommei et al, 2006). It may disrupt the homeostasis of intracellular Ca 2+ , resulting in the increase of dead cell population in the cells simultaneously treated with CdCl 2 .…”