Unconventional localization of PAI-1 in PML bodies: A possible link with cellular growth of endothelial cells

Autor: Pragya Gehlot, Daniela Brünnert, Vibha Kaushik, Arpana Yadav, Saloni Bage, Kritika Gaur, Mahesh Saini, Jens Ehrhardt, Gowrang Kasaba Manjunath, Abhishek Kumar, Neena Kasliwal, Ajay Kumar Sharma, Marek Zygmunt, Pankaj Goyal
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Biochemistry and Biophysics Reports, Vol 39, Iss , Pp 101793- (2024)
Druh dokumentu: article
ISSN: 2405-5808
DOI: 10.1016/j.bbrep.2024.101793
Popis: Plasminogen activator inhibitor-1 (PAI-1/Serpin E1) is classically known for its antifibrinolytic activity via inhibiting uPA and tPA of the fibrinolytic pathway. PAI-1 has a paradoxical role in tumor progression, and its molecular functions are poorly understood. PAI-1 is a widely accepted secretory protease inhibitor, however, a study suggested the localization of PAI-1 in the cytoplasm and the nucleus. Besides the plethora of its biological functions as a secretory protein, intracellular localization, and functions of PAI-1 remain unexplored at the molecular level. In this study, using various in silico approaches, we showed that PAI-1 possesses a nuclear export signal. Using the CRM1-specific inhibitor leptomycin B, we demonstrated that PAI-1 has a functional CRM1-dependent NES, indicating the possibility of its nuclear localization. Further, we confirm that PAI-1 is localized in the nucleus of endothelial cells using fluorescence microscopy and immunoprecipitation. Notably, we identified an unconventional distribution of PAI-1 in the PML bodies of the nucleus of normal endothelial cells, while the protein was restricted in the cytoplasm of slow-growing cells. The data showed that the localization of PAI-1 in PML bodies is highly correlated with the growth potential of endothelial cells. This conditional nucleocytoplasmic shuttling of PAI-1 during the aging of cells could impart a strong link to its age-related functions and tumor progression. Together, this study identifies the novel behavior of PAI-1 that might be linked with cell aging and may be able to unveil the elusive role of PAI-1 in tumor progression.
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