interorganellar

Interorganellar refers to processes, structures, or communications that occur between organelles within a cell. The term is used to emphasize the integrated nature of organelle function, where physical contacts and signaling pathways coordinate metabolism, signaling, and organelle dynamics. These interorganelle interactions can involve direct membrane contact, trafficking of lipids and proteins, and exchange of ions and metabolites, enabling a coherent cellular response to changing conditions.

Prominent examples include mitochondria–endoplasmic reticulum contact sites (MAMs), which facilitate calcium homeostasis, lipid transfer, and mitochondrial fission. Other organelle pairs, such as ER–Golgi, ER–endosome, and ER–lysosome contacts, support vesicular trafficking and lipid exchange. Peroxisomes also interface with the ER for lipid metabolism and biogenesis. Interorganellar communication is also evident in mitochondria–lysosome contacts involved in mitophagy and quality control. These contacts are dynamic and condition-specific, expanding or contracting as needed.

Physical contacts are mediated by tethering proteins and membrane contact site complexes, and transfer can be assisted by lipid transfer proteins and ion channels. Regulation depends on cellular energy status, stress signals, and developmental cues, making interorganelle communication a central aspect of organelle plasticity and homeostasis.

Research into interorganellar communication uses advanced microscopy, proximity labeling, and omics approaches to map contact sites, identify tethering factors, and understand functional consequences for health and disease. Disruptions in interorganellar signaling have been linked to neurodegenerative and metabolic disorders, highlighting its importance in cellular physiology.