PKC412 normalizes mutation-related keratin filament disruption and hepatic injury in mice by promoting keratin-myosin binding
| Autor: | Guo Zhong Tao, Qing Xie, Sujith V.W. Weerasinghe, M. Bishr Omary, Raymond Kwan, Robert S. Adelstein, Natasha T. Snider, Lu Chen, Mary Anne Conti, Koksun Looi |
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| Rok vydání: | 2015 |
| Předmět: |
chemistry.chemical_classification
Keratin Filament integumentary system Hepatology Liver Diseases Intermediate Filaments Mice Transgenic macromolecular substances Biology Myosins Staurosporine Molecular biology Keratin 18 Keratin 5 Mice chemistry Myosin binding Keratin Myosin Mutation Animals Keratins Intermediate filament Cytoskeleton Protein Binding |
| Zdroj: | Hepatology (Baltimore, Md.). 62(6) |
| ISSN: | 1527-3350 |
| Popis: | Keratins, among other cytoskeletal intermediate filament proteins, are mutated at a highly conserved arginine with consequent severe disease phenotypes due to disruption of keratin filament organization. We screened a kinase inhibitor library, using A549 cells that are transduced with a lentivirus keratin 18 (K18) construct, to identify compounds that normalize filament disruption due to K18 Arg90Cys mutation at the conserved arginine. High-throughput screening showed that PKC412, a multikinase inhibitor, ameliorated K18 Arg90Cys-mediated keratin filament disruption in cells and in the livers of previously described transgenic mice that overexpress K18 Arg90Cys. Furthermore, PKC412 protected cultured A549 cells that express mutant or wild-type K18 and mouse livers of the K18 Arg90Cys-overexpressing transgenic mice from Fas-induced apoptosis. Proteomic analysis of proteins that associated with keratins after exposure of K18-expressing A549 cells to PKC412 showed that nonmuscle myosin heavy chain-IIA (NMHC-IIA) partitions with the keratin fraction. The nonmuscle myosin-IIA (NM-IIA) association with keratins was confirmed by immune staining and by coimmunoprecipitation. The keratin–myosin association is myosin dephosphorylation–dependent; occurs with K8, the obligate K18 partner; is enhanced by PKC412 in cells and mouse liver; and is blocked by hyperphosphorylation conditions in cultured cells and mouse liver. Furthermore, NMHC-IIA knockdown inhibits PKC412-mediated normalization of K18 R90C filaments. Conclusion: The inhibitor PKC412 normalizes K18 Arg90Cys mutation-induced filament disruption and disorganization by enhancing keratin association with NM-IIA in a myosin dephosphorylation–regulated manner. Targeting of intermediate filament disorganization by compounds that alter keratin interaction with their associated proteins offers a potential novel therapeutic approach for keratin and possibly other intermediate filament protein–associated diseases. (Hepatology 2015) |
| Databáze: | OpenAIRE |
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