Phase to Phase with TDP-43.

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• TDP-43 is a nuclear protein vital for RNA metabolism.
• Dysfunctional TDP-43 is implicated in amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD).
• Pathological inclusions in ALS/FTD neurons contain modified TDP-43.

Purpose of the Study:

• To review the physiological and pathological roles of TDP-43.
• To analyze TDP-43's structural domains and their contribution to function and disease.
• To emphasize the C-terminal prion-like region in TDP-43 pathology.

Main Methods:

• Literature review of TDP-43 research.
• Analysis of structural studies on TDP-43 domains.
• Discussion of phase transitions (soluble, droplet, aggregate).

Main Results:

• TDP-43's C-terminal prion-like domain is crucial for pathology.
• This domain forms phase-separated liquid droplets via a partially populated α-helix.
• Liquid droplets, like stress granules, may be precursors to pathological TDP-43 aggregates.

Conclusions:

• Structural insights into TDP-43's C-terminal domain explain its role in liquid droplet formation.
• This mechanism links environmental stressors to the etiology of TDP-43 proteinopathies.
• Understanding TDP-43 phase transitions is key to elucidating ALS/FTD pathogenesis.