Document Type
Article
Publication Date
2020
Keywords
TAR DNA-binding protein 43 (TDP-43, TARDBP), ALS (Lou Gehrig disease), stress granule, protein–protein interaction, protein dynamic, intrinsically disordered protein, ALS, FTLD, Granulins, liquid–liquid phase separation, progranulin
Digital Object Identifier (DOI)
https://doi.org/10.1074/jbc.RA119.011501
Abstract
TAR DNA-binding protein 43 (TDP-43) has emerged as a key player in many neurodegenerative pathologies, including frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). Hallmarks of both FTLD and ALS are the toxic cytoplasmic inclusions of the prion-like C-terminal fragments of TDP-43 CTD (TDP-43 C-terminal domain), formed upon proteolytic cleavage of full-length TDP-43 in the nucleus and subsequent transport to the cytoplasm. Both full-length TDP-43 and its CTD are also known to form stress granules by coacervating with RNA in the cytoplasm during stress and may be involved in these pathologies. Furthermore, mutations in the PGRN gene, leading to haploinsufficiency and diminished function of progranulin (PGRN) protein, are strongly linked to FTLD and ALS. Recent reports have indicated that proteolytic processing of PGRN to smaller protein modules called granulins (GRNs) contributes to FTLD and ALS progression, with specific GRNs exacerbating TDP-43–induced cytotoxicity. Here we investigated the interactions between the proteolytic products of both TDP-43 and PGRN. Based on structural disorder and charge distributions, we hypothesized that GRN-3 and GRN-5 could interact with the TDP-43 CTD. We show that, under both reducing and oxidizing conditions, GRN-3 and GRN-5 interact with and differentially modulate TDP-43 CTD aggregation and/or liquid–liquid phase separation in vitro. GRN-3 promoted insoluble aggregates of the TDP-43 CTD while GRN-5 mediated liquid–liquid phase separation. These results constitute the first observation of an interaction between GRNs and TDP-43, suggesting a mechanism by which attenuated PGRN function could lead to familial FTLD or ALS.
Rights Information
This work is licensed under a Creative Commons Attribution 4.0 License.
Was this content written or created while at USF?
Yes
Citation / Publisher Attribution
Journal of Biological Chemistry, v. 295, issue 8, p. 2506-2519
Scholar Commons Citation
Bhopatkar, Anukool A.; Uversky, Vladimir N.; and Rangachari, Vijayaraghavan, "Granulins Modulate Liquid–liquid Phase Separation and Aggregation of the Prion-like C-terminal Domain of the Neurodegeneration-associated Protein TDP-43" (2020). Molecular Medicine Faculty Publications. 161.
https://digitalcommons.usf.edu/mme_facpub/161
Supplementary Material
