Dynamic regulation of the cellular proteome is mainly controlled in the endoplasmic
reticulum (ER). Accumulation of misfolded proteins due to ER stress leads to the activation
of unfolded protein response (UPR). The primary role of UPR is to reduce the bulk
of damages and try to drive back the system to the former or a new homeostatic state
by autophagy, while an excessive level of stress results in apoptosis. It has already
been proven that the proper order and characteristic features of both surviving and
self-killing mechanisms are controlled by negative and positive feedback loops, respectively.
The new results suggest that these feedback loops are found not only within but also
between branches of the UPR, fine-tuning the response to ER stress. In this review,
we summarize the recent knowledge of the dynamical characteristic of endoplasmic reticulum
stress response mechanism by using both theoretical and molecular biological techniques.
In addition, this review pays special attention to describing the mechanism of action
of the dynamical features of the feedback loops controlling cellular life-and-death
decision upon ER stress. Since ER stress appears in diseases that are common worldwide,
a more detailed understanding of the behaviour of the stress response is of medical
importance.
