Vacuolar protein sorting

Vacuolar protein sorting (VPS) is a process that occurs in the cell where proteins are sorted and transported to their appropriate destinations. This process is crucial for the proper functioning of the cell and is highly regulated.

Overview

Vacuolar protein sorting is a process that occurs in the endomembrane system of the cell. This system includes the endoplasmic reticulum, Golgi apparatus, and lysosomes. The process involves the sorting and packaging of proteins into vesicles, which are then transported to their appropriate destinations within or outside the cell.

Mechanism

The process of vacuolar protein sorting begins in the endoplasmic reticulum, where proteins are synthesized. These proteins are then transported to the Golgi apparatus, where they are modified and sorted. The sorted proteins are packaged into vesicles, which bud off from the Golgi apparatus and are transported to their destinations.

The transport of vesicles is facilitated by molecular motors, which move along cytoskeletal tracks. The direction of vesicle transport is determined by the type of molecular motor and the type of cytoskeletal track.

Regulation

The process of vacuolar protein sorting is highly regulated to ensure that proteins are delivered to the correct destinations. This regulation is achieved through the action of various proteins, including small GTPases, SNAREs, and coat proteins.

Small GTPases regulate the formation and budding of vesicles. SNARE proteins mediate the fusion of vesicles with their target membranes. Coat proteins are involved in the selection of cargo proteins and the formation of vesicles.

Clinical significance

Defects in vacuolar protein sorting can lead to various diseases, including neurodegenerative diseases, cancer, and infectious diseases. For example, mutations in VPS genes have been associated with Parkinson's disease and Alzheimer's disease. In addition, some viruses and bacteria exploit the VPS pathway to enter and exit cells.

See also

• Protein targeting
• Endocytosis
• Exocytosis