Membrane fusion

Membrane Fusion is a fundamental biological process that involves the merging of two separate lipid bilayers into a single continuous bilayer. This process is essential for various cellular activities such as cell division, virus infection, and neurotransmitter release.

Overview

Membrane fusion is a critical process in eukaryotic cells. It is involved in a variety of cellular processes, including the transport of proteins and lipids between different cellular compartments. The process is facilitated by a group of proteins known as SNARE proteins.

Mechanism

The mechanism of membrane fusion involves several steps. Initially, the two membranes come into close proximity, facilitated by tethering proteins. Following this, SNARE proteins on both membranes interact to form a SNARE complex, pulling the membranes closer together. The final step is the merging of the two lipid bilayers, resulting in the formation of a fusion pore.

Role in Cellular Processes

Membrane fusion plays a crucial role in various cellular processes. In cell division, it helps in the formation of the mitotic spindle. In neurotransmission, it aids in the release of neurotransmitters from synaptic vesicles. It is also involved in the process of virus infection, where it facilitates the entry of the virus into the host cell.

Role in Disease

Abnormalities in membrane fusion can lead to various diseases. For example, defects in the SNARE proteins can lead to neurological disorders such as Alzheimer's disease and Parkinson's disease. Similarly, viruses such as HIV and Influenza exploit the process of membrane fusion to infect host cells.

See Also

• Cell membrane
• Vesicle (biology and chemistry)
• Endocytosis
• Exocytosis