Question

The correct folding of proteins is necessary to maintain healthy cells and tissues. Unfolded proteins are responsible for such neurodegenerative disorders as Alzheimer's disease, Huntington's disease, and Creutzfeldt-Jakob disease (the specific faulty protein is different for each disease). What is the ultimate fate of these disease-causing, unfolded proteins?

(a) They are degraded.
(b) They bind a different target protein. (c) They form structured filaments.
(d) They form protein aggregates.

Answer 1

The disease-causing unfolded proteins ultimately form protein aggregates. This aggregation leads to the formation of toxic amyloid plaques, which characterizes diseases such as Alzheimer's and results in neurodegeneration.

Step-by-step explanation:

The ultimate fate of these disease-causing, unfolded proteins is (d) They form protein aggregates.

When proteins are misfolded, they lose their functional shape and can no longer perform their intended biological tasks. Instead, these misfolded proteins tend to stick together, forming protein aggregates. Diseases such as Alzheimer's, Huntington's disease, and Creutzfeldt-Jakob disease are characterized by the accumulation of these toxic aggregates, leading to the term proteopathy. In Alzheimer's disease, for example, the formation of amyloid plaques in the brain is a direct result of protein misfolding and subsequent aggregation.

These aggregates disrupt cell function and are toxic to cells leading to neurodegeneration. Therapeutic strategies are being developed that aim to disrupt the formation of these aggregates or prevent the misfolding of proteins altogether.