Bioinformatic identification of previously unrecognized amyloidogenic proteins

• Published in: The Journal of biological chemistry Vol. 298; no. 5; p. 101920
• Main Authors: Rosenberg, Gregory M., Murray, Kevin A., Salwinski, Lukasz, Hughes, Michael P., Abskharon, Romany, Eisenberg, David S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2022; American Society for Biochemistry and Molecular Biology
• Subjects: amyloid; Amyloid - genetics; Amyloid - metabolism; Amyloidogenic Proteins - genetics; Amyloidosis - metabolism; Amyloidosis - pathology; Charcot–Marie–Tooth disease electron microscopy; Computational Biology; Humans; intrinsically disordered protein; low-complexity domain; Mutation; protein structure; Proteome - genetics; protein structure; low-complexity domain; ThT; amyloid; intrinsically disordered protein; TFG; Charcot–Marie–Tooth disease electron microscopy; LCD; NIH
• DOI: 10.1016/j.jbc.2022.101920
• ISSN: 0021-9258; 1083-351X

Low-complexity domains (LCDs) of proteins have been shown to self-associate, and pathogenic mutations within these domains often drive the proteins into amyloid aggregation associated with disease. These domains may be especially susceptible to amyloidogenic mutations because they are commonly intrinsically disordered and function in self-association. The question therefore arises whether a search for pathogenic mutations in LCDs of the human proteome can lead to identification of other proteins associated with amyloid disease. Here, we take a computational approach to identify documented pathogenic mutations within LCDs that may favor amyloid formation. Using this approach, we identify numerous known amyloidogenic mutations, including several such mutations within proteins previously unidentified as amyloidogenic. Among the latter group, we focus on two mutations within the TRK-fused gene protein (TFG), known to play roles in protein secretion and innate immunity, which are associated with two different peripheral neuropathies. We show that both mutations increase the propensity of TFG to form amyloid fibrils. We therefore conclude that TFG is a novel amyloid protein and propose that the diseases associated with its mutant forms may be amyloidoses.