@article{8d1593837ca34c468a941cee6f40fd2e,
title = "A myosin-Va tail fragment sequesters dynein light chains leading to apoptosis in melanoma cells",
abstract = "Previous studies proposed that myosin-Va regulates apoptosis by sequestering pro-apoptotic Bmf to the actin cytoskeleton through dynein light chain-2 (DLC2). Adhesion loss or other cytoskeletal perturbations would unleash Bmf, allowing it to bind and inhibit pro-survival Bcl2 proteins. Here, we demonstrated that overexpression of a myosin-Va medial tail fragment (MVaf) harboring the binding site for DLC2 dramatically decreased melanoma cell viability. Morphological and molecular changes, including surface blebbing, mitochondrial outer membrane permeabilization, cytochrome-c and Smac release, as well as caspase-9/-3 activation and DNA fragmentation indicated that melanoma cells died of apoptosis. Immobilized MVaf interacted directly with DLCs, but complexed MVaf/DLCs did not interact with Bmf. Overexpression of DLC2 attenuated MVaf-induced apoptosis. Thus, we suggest that, MVaf induces apoptosis by sequestering DLC2 and DLC1, thereby unleashing the pair of sensitizer and activator BH3-only proteins Bmf and Bim. Murine embryonic fibroblasts (MEFs) lacking Bim and Bmf or Bax and Bak were less sensitive to apoptosis caused by MVaf expression than wild-type MEFs, strengthening the putative role of the intrinsic apoptotic pathway in this response. Finally, MVaf expression attenuated B16-F10 solid tumor growth in mice, suggesting that this peptide may be useful as an apoptosis-inducing tool for basic and translational studies.",
keywords = "Apoptosis, Bmf, DLC1/DLC2, Melanoma, Myosin-Va",
author = "Izidoro-Toledo, {T. C.} and Borges, {A. C.} and Araujo, {D. D.} and {Leit{\~a}o Mazzi}, {D. P.S.} and Junior, {F. O.Nascimento} and Sousa, {J. F.} and Alves, {C. P.} and Paiva, {A. P.B.} and Trindade, {D. M.} and Patussi, {E. V.} and Peixoto, {P. M.} and Kinnally, {K. W.} and Espreafico, {E. M.}",
note = "Funding Information: Acknowledgements. We are grateful to technicians Silmara Reis Banzi and Domingos E Pitta for expert technical assistance with protein purification and antibody production; to Maria Dolores S Pereira, Maria Teresa P Maglia and Jos{\'e} Augusto Maulin for assistance with electron microscopy; to Dr. Marcia Graeff for the technical supervision on the confocal microscopy analyses in the {\textquoteleft}Centro Multiusu{\'a}rio de Microscopia Confocal-FMRP-USP{\textquoteright}; to Benedita O de Souza for general lab assistance; and to Domingos de Souza for biotery assistance. We also thank Patricia Viana Bonini Palma and Camila Cristina de Oliveira Menezes Bonaldo for help with cell sorting at the Flow Cytometry Lab, Hemotherapy Center of Ribeir{\~a}o Preto. We are thankful to Dr. Stanley J Korsmeyer (Howard Hughes Medical Institute, Departments of Pathology and Medicine, Harvard Medical School, Dana-Farber Cancer Institute, Boston, Massachusetts 02115,USA) for the Bcl2 construct in the pGEX-4T-3 vector; Dr. Foued S Espindola (University Federal of Uberl{\^a}ndia, Uberl{\^a}ndia MG, Brazil) for the cDNA clone EST63321 obtained from ATCC and anti-DLC Clamydomonas R-4058; Dr. David N Levy (New York University, New York, NY, USA) for helping us with the construction of vector pLVX-EGFP. We are also grateful to the following researchers for providing cell lines: Dr. John Pawelek (Yale University, New Haven, CT, USA), Dr. Meenhard Herlyn (The Wistar Institute Cancer Center), Dr. Roger J Davis (Howard Hughes Medical Institute, Massachusetts Medical School), Dr. Andreas Villunger (Innsbruck Medical University, Austria) and Professor Andreas Strasser (Walter and Eliza Hall Institute, Melbourne, Australia). This work was supported by grants from Fundac¸{\~a}o de Amparo {\`a} Pesquisa do Estado de S{\~a}o Paulo (FAPESP #2009/50167-3 – PI: EME), CNPq (# 401322/2005-0 – PI: EME) and FAEPA. CAPES provided a doctorate fellowship to TCIT and CPA. FAPESP provided a technical fellowship to APBP, master fellowship to DDA and DMT, doctorate fellowship to JFS and EVP, postdoctoral fellowship to JFS and to DPSLM. CNPq provided a research fellowship to EME, master and doctorate to ACB, international doctorate fellowship to ACB and to CPA, undergraduate student fellowship to FONJ, and post-doctorate fellowship to JFS. We thank Ricardo GP Ramos and Roy E Larson for critical reading of the revised version.",
year = "2013",
month = mar,
doi = "10.1038/cddis.2013.45",
language = "English (US)",
volume = "4",
pages = "e547",
journal = "Cell Death and Disease",
issn = "2041-4889",
publisher = "Nature Publishing Group",
number = "3",
}