2. Academic Validation
  3. Wiskostatin and other carbazole scaffolds as off target inhibitors of dynamin I GTPase activity and endocytosis

Wiskostatin and other carbazole scaffolds as off target inhibitors of dynamin I GTPase activity and endocytosis

  • Eur J Med Chem. 2022 Dec 15;247:115001. doi: 10.1016/j.ejmech.2022.115001.
Peter J Cossar 1,  David Cardoso 2,  Daniel Mathwin 1,  Cecilia C Russell 1,  Beatrice Chiew 1,  Michael P Hamilton 1,  Jennifer R Baker 1,  Kelly A Young 1,  Ngoc Chau 2,  Phillip J Robinson 2,  Adam McCluskey 3
Affiliations

Affiliations

  • 1 Chemistry, School of Environmental & Life Sciences, The University of Newcastle, University Drive, Callaghan NSW, 2308, Australia.
  • 2 Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia.
  • 3 Chemistry, School of Environmental & Life Sciences, The University of Newcastle, University Drive, Callaghan NSW, 2308, Australia. Electronic address: [email protected].
PMID: 36577213 DOI: 10.1016/j.ejmech.2022.115001
Abstract

Wiskostatin (1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol) (1) is a carbazole-based compound reported as a specific and relatively potent inhibitor of the N-WASP actin remodelling complex (S-isomer EC50 = 4.35 μM; R-isomer EC50 = 3.44 μM). An NMR solution structure showed that wiskostatin interacts with a cleft in the regulatory GTPase binding domain of N-WASP. However, numerous studies have reported wiskostatin's actions on membrane transport and cytokinesis that are independent of the N-WASP-Arp2/3 complex pathway, but offer limited alternative explanation. The large GTPase, Dynamin has established functional roles in these pathways. This study reveals that wiskostatin and its analogues, as well as other carbazole-based compounds, are inhibitors of helical Dynamin GTPase activity and endocytosis. We characterise the effects of wiskostatin on in vitro Dynamin GTPase activity, in-cell endocytosis, and determine the importance of wiskostatin functional groups on these activities through design and synthesis of libraries of wiskostatin analogues. We also examine whether other carbazole-based scaffolds frequently used in research or the clinic also modulate Dynamin and endocytosis. Understanding off-targets for compounds used as research tools is important to be able to confidently interpret their action on biological systems, particularly when the target and off-targets affect overlapping mechanisms (e.g. cytokinesis and endocytosis). Herein we demonstrate that wiskostatin is a Dynamin Inhibitor (IC50 20.7 ± 1.2 μM) and a potent inhibitor of clathrin mediated endocytosis (IC50 = 6.9 ± 0.3 μM). Synthesis of wiskostatin analogues gave rise to 1-(9H-carbazol-9-yl)-3-((4-methylbenzyl)amino)propan-2-ol (35) and 1-(9H-carbazol-9-yl)-3-((4-chlorobenzyl)amino)propan-2-ol (43) as potent Dynamin inhibitors (IC50 = 1.0 ± 0.2 μM), and (S)-1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol (8a) and (R)-1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol (8b) that are amongst the most potent inhibitors of clathrin mediated endocytosis yet reported (IC50 = 2.3 ± 3.3 and 2.1 ± 1.7 μM, respectively).

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