Contents lists available at ScienceDirect International Journal of Biochemistry and Cell Biology journal homepage: www.elsevier.com/locate/biocel Ubiquitin ligase LRSAM1 suppresses neurodegenerative diseases linked aberrant proteins induced cell death Ribhav Mishra a , Ayeman Amanullah a , Arun Upadhyay a , Rohan Dhiman c , Ankur Rakesh Dubey a , Sarika Singh d , Amit Prasad b , Amit Mishra a, * a Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, 342037, India b School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India c Laboratory of Mycobacterial Immunology, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India d Toxicology and Experimental Medicine Division, CSIR-Central Drug Research Institute, Academy of Scientific & Innovative Research (AcSIR), Lucknow, 226031, UP, India ARTICLEINFO Keywords: LRSAM1 Hsp70 Misfolded proteins Cell death Ubiquitin ligase ABSTRACT Accumulation of aberrant misfolded proteins is a major hallmark of several neurodegenerative diseases. Intracellular accumulations of such abnormal proteins are selectively cleared by the ubiquitin-proteasome system (UPS). But how the failure of misfolded protein degradation cause proteinopathies is still an unanswered question?. Previous studies have suggested that few selective quality control (QC) E3 ubiquitin ligase from the UPS can selectively target insoluble aggregated proteins for their intracellular degradation. Few reports suggest that lack or aberrant functions of QC E3 ubiquitin ligases can be a possible causative factor of neurodegeneration and aging. Earlier findings indicated that leucine-rich repeat and sterile alpha motif containing-1 (LRSAM1) is associated with Charcot-Marie-Tooth Type 2P (CMT2P) disease in which loss of LRSAM1 function sensitizes peripheral axons for degeneration. Here, our current study for the first time demonstrates that E3 ubiquitin Ligase LRSAM1 is a really interesting new gene (RING) class protein which suppresses the accumulation of misfolded protein aggregates and also alleviates their deleterious cytotoxic effects. We have also observed that LRSAM1 expression is elevated under neurodegenerative stress conditions, and partial depletion of LRSAM1 endogenous levels aggravates mitochondrial abnormalities and severely affects cell survival during proteotoxic insults. Overall, our current finding indicates that LRSAM1 can alleviate cytotoxic insults mediated by a variety of neurodegeneration linked proteotoxic stress events, and most likely LRSAM1 interplay a significant role in between different components of cellular protein quality control mechanism. This study will also allow us to better comprehend the problem of proteinopathies linked with aberrant protein accumulation and open new possibilities to better elucidate the molecular mechanisms involved in the pathologies of neurodegeneration and aging. 1. Introduction Protein folding and degradation of abnormal proteins are critical mechanisms of the protein quality control system of the cells that maintain proteostasis and stability under destabilization events (Chen et al., 2011; Díaz-Villanueva et al., 2015). Under proteotoxic stresses, the cell employs a different and wide range of physiological mechanisms, including autophagy and the UPS, to limit the failure of proteostasis (Goldberg, 2003; Ogata et al., 2006). Previous findings suggest that genotoxic stress events, including the accumulation of misfolded proteins, contribute as imperfect molecular factors that affect overall cellular fitness and cause fatal neurodegenerative diseases (Amanullah et al., 2017; Ross and Poirier, 2004a,b; Shastry, 2003). UPS has been linked to the regulation of cellular survival and the stress https://doi.org/10.1016/j.biocel.2020.105697 Received 5 November 2019; Received in revised form 5 January 2020; Accepted 19 January 2020 Abbreviations: ALS, Amyotrophic Lateral Sclerosis; CHIP, C-terminus of Hsc70-Interacting Protein; CMT2P, Charcot-Marie-Tooth Type 2P; DMSO, Dimethyl Sulfoxide; E6-AP, E6-Associated Protein; ER, Endoplasmic Reticulum; H 2 O 2 , Hydrogen Peroxide; HRP, Horse-Radish Peroxidase; HS, Heat Shocked; IB, Inclusion Bodies; ITCH, Itchy E3 Ubiquitin Protein Ligase; MGRN1, Mahogunin Ring Finger-1; MTOC, Microtubule-Organizing Center; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide; PBS, Phosphate-Buffered Saline; PQC, Protein Quality Control; QC, Quality Control; TBST, Tris-buffered saline with 0.1 % Tween-20; TSG101, Tumor Susceptibility Gene 101; TUNNEL, Terminal deoxynucleotidyl Transferase (TdT) dUTP Nick-End Labeling; UPS, Ubiquitin-Proteasome System ⁎ Corresponding author at: Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, 342037, India. E-mail address: amit@iitj.ac.in (A. Mishra). International Journal of Biochemistry and Cell Biology 120 (2020) 105697 Available online 23 January 2020 1357-2725/ © 2020 Elsevier Ltd. All rights reserved. T