Exopher

Exopher

Diagram of an exopher

An exopher is a cellular structure that is involved in the process of removing large aggregates and damaged organelles from cells. This process is crucial for maintaining cellular health and function, particularly in neurons and other long-lived cells. Exophers are a type of extracellular vesicle, but they are distinct in their size and function compared to other vesicles such as exosomes and microvesicles.

Structure and Formation

Exophers are relatively large vesicular structures that can encapsulate cellular debris, including protein aggregates, damaged mitochondria, and other organelles. The formation of exophers is thought to be a response to cellular stress, where the cell packages unwanted or potentially harmful components into a vesicle that is then extruded from the cell.

The process of exopher formation begins with the aggregation of cellular debris within the cytoplasm. This is followed by the budding of the plasma membrane to envelop the debris, forming a large vesicle. The exopher is then released from the cell into the extracellular space.

Function

The primary function of exophers is to maintain cellular homeostasis by removing potentially toxic materials from the cell. This is particularly important in neurons, where the accumulation of damaged proteins and organelles can lead to neurodegenerative diseases. By extruding these materials, exophers help to prevent cellular dysfunction and promote longevity.

Exophers have been observed in various model organisms, including Caenorhabditis elegans, where they play a role in the health and function of neuronal cells. The study of exophers is ongoing, with researchers investigating their role in human health and disease.

Biological Significance

The discovery of exophers has provided new insights into the mechanisms of cellular waste management. They represent a novel pathway for the disposal of large cellular components that cannot be degraded by the proteasome or autophagy pathways. This is particularly significant in the context of aging and age-related diseases, where the accumulation of cellular debris is a common feature.

Related pages

• Extracellular vesicle
• Autophagy
• Neurodegenerative disease
• Cellular homeostasis