cytolytic granule membrane

Definition

Target type: cellularcomponent

The lipid bilayer surrounding the cytolytic granule. [PMID:17272266, PMID:21247065]

The cytolytic granule membrane is a specialized membrane that surrounds the cytotoxic granules found in cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. These granules contain cytotoxic proteins, such as perforin and granzyme, which are essential for the elimination of infected or cancerous cells. The cytolytic granule membrane is characterized by its unique composition and structure, which play crucial roles in the regulated release of cytotoxic proteins.

The membrane is composed of a phospholipid bilayer, similar to other cellular membranes, but it also contains a number of specialized proteins that are not found in other membranes. These proteins include:

**Perforin:** A pore-forming protein that creates holes in the target cell membrane. Perforin is essential for the entry of granzyme into the target cell.

**Granzyme:** A family of serine proteases that induce apoptosis in target cells. Granzymes are delivered into target cells through the pores created by perforin.

**Rab27a:** A small GTPase that regulates the docking and fusion of cytolytic granules with the plasma membrane. Rab27a is essential for the exocytosis of cytotoxic granules.

**Syntaxin 11:** A SNARE protein that interacts with other SNARE proteins and Rab27a to facilitate the fusion of cytolytic granules with the plasma membrane.

**Munc13-4:** A protein that promotes the assembly of the SNARE complex and facilitates the fusion of cytolytic granules with the plasma membrane.

**Lyst:** A protein involved in the biogenesis of cytolytic granules. Mutations in Lyst can lead to the Chediak-Higashi syndrome, a rare genetic disorder characterized by impaired immune function.

**Structure:** The cytolytic granule membrane is a highly dynamic structure that is constantly undergoing changes in its composition and structure. The membrane is highly curved, which helps to concentrate cytotoxic proteins within the granule. The membrane is also highly flexible, which allows it to fuse with the plasma membrane and release cytotoxic proteins into the extracellular space.

**Function:** The cytolytic granule membrane plays a critical role in the cytotoxic activity of CTLs and NK cells. The membrane serves as a barrier that prevents the premature release of cytotoxic proteins from the granules. It also facilitates the regulated release of cytotoxic proteins in response to specific stimuli. The release of cytotoxic proteins from the cytolytic granules is a tightly controlled process that involves a series of signaling events and protein interactions.

In summary, the cytolytic granule membrane is a specialized membrane that is essential for the cytotoxic activity of CTLs and NK cells. It is characterized by its unique composition, structure, and dynamic properties, which play crucial roles in the regulated release of cytotoxic proteins.'
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Proteins (1)

Compounds (5)