dense core granule

Definition

Target type: cellularcomponent

Electron-dense organelle with a granular internal matrix; contains proteins destined to be secreted. [NIF_Subcellular:sao772007592, PMID:14690495]

Dense core granules (DCGs) are membrane-bound organelles found in various cell types, particularly neurons and endocrine cells. They are characterized by their electron-dense content, which primarily consists of bioactive molecules such as neuropeptides, hormones, and neurotransmitters. These molecules are packaged and stored within the granules in a concentrated form, allowing for their efficient release upon cellular stimulation.

The cellular components of DCGs can be broadly divided into three main categories:

1. **Membrane:** The DCG membrane is a specialized lipid bilayer that encloses the granule's contents. It is enriched with specific proteins, including:
- **Sorting receptors:** These proteins play a crucial role in directing the targeted delivery of specific cargos to the DCG.
- **SNARE proteins:** These proteins facilitate the fusion of the DCG membrane with the plasma membrane, enabling the release of the stored contents.
- **Other integral membrane proteins:** These proteins contribute to the structural integrity and functionality of the DCG membrane.

2. **Matrix:** The matrix refers to the dense, amorphous material that fills the interior of the DCG. It serves as the primary storage compartment for the bioactive molecules. The matrix is composed of:
- **Proteins:** These proteins interact with the cargo molecules, forming complexes that ensure their proper packaging and stability within the granule.
- **Lipids:** The matrix also contains lipids, which contribute to the overall structure and fluidity of the granule's interior.
- **Carbohydrates:** Carbohydrates can be present in the matrix, potentially playing a role in cargo sorting and granule stability.

3. **Cargo:** The cargo represents the bioactive molecules that are stored and transported within the DCG. The specific cargo composition varies depending on the cell type and its function. Common examples include:
- **Neuropeptides:** These small peptides play a role in neurotransmission and other signaling pathways.
- **Hormones:** These signaling molecules regulate various physiological processes throughout the body.
- **Neurotransmitters:** These chemical messengers facilitate communication between neurons.

In summary, the cellular components of DCGs represent a complex and highly regulated system that ensures the efficient storage, transport, and release of bioactive molecules. This process plays a crucial role in maintaining cellular homeostasis and mediating diverse physiological functions.'
"

Proteins (3)

Compounds (13)