FIGURE 1.

An overview of the key components of mitochondrial dynamics-ER communication and maintenance of cellular physiology. Mitochondria undergo two successive and opposite processes related to membranes: fission and fusion. Depending on the cellular environment and circumstances, the balance between fission and fusion can change, and the balance tends to favor one of these two processes. When cells are subjected to mild stress, mitochondria form an elongated and interconnected network to adapt to nutrient deficiencies while adapting to cellular stress. In contrast, under severe stress, mitochondria present a fragmented shape. Mitochondria and ER are in close proximity to each other and form the MAM. The MAM allows efficient Ca²⁺-stable exchange between the ER and mitochondria through the IP₃R, VDAC mitochondrial calcium unidirectional transport protein (MCU) and PTP. Several proteins involved in mitochondrial fission, such as Mff and Fis1 mediate the localization of Drp1 on the ER, suggesting the existence of other unknown pathways to control ER-controlled mitochondrial dynamics.