What is one consequence of a malfunctioning endoplasmic reticulum?

The endoplasmic reticulum (ER) plays a crucial role in the synthesis and folding of proteins. When the ER malfunctions, one significant consequence is the accumulation of misfolded proteins. The ER is responsible for properly folding proteins and ensuring they are functional before they are transported to their next destination within the cell or secreted outside of it. If the folding process is disrupted due to ER stress, protein misfolding can occur, leading to a backlog of improperly folded proteins.

The accumulation of these misfolded proteins can trigger the unfolded protein response (UPR), a cellular stress response aimed at restoring normal function by enhancing the protein-folding capacity of the ER or, if the stress is unresolved, leading to cell death. Therefore, the connection between a malfunctioning endoplasmic reticulum and the accumulation of misfolded proteins underscores the critical importance of the ER in maintaining cellular health and function.