positive regulation of cytosolic calcium ion concentration

Definition

Target type: biologicalprocess

Any process that increases the concentration of calcium ions in the cytosol. [GOC:ai]

Positive regulation of cytosolic calcium ion concentration is a fundamental cellular process that involves a complex interplay of signaling pathways and molecular mechanisms. It is essential for a wide range of cellular functions, including muscle contraction, neurotransmission, cell growth, and apoptosis.

The increase in cytosolic calcium concentration is typically triggered by extracellular stimuli, such as hormones, neurotransmitters, or mechanical stress. These stimuli activate various signaling pathways that ultimately lead to the opening of calcium channels in the plasma membrane or intracellular calcium stores.

**Key mechanisms involved in positive regulation of cytosolic calcium concentration:**

**1. Voltage-gated calcium channels (VGCCs):**
- Located in the plasma membrane, VGCCs are activated by changes in membrane potential.
- Upon depolarization, these channels open, allowing calcium ions to flow into the cytosol.

**2. Ligand-gated calcium channels (LGCCs):**
- Activated by specific ligands, such as neurotransmitters or hormones.
- These channels open in response to ligand binding, enabling calcium influx.

**3. Store-operated calcium channels (SOCCs):**
- Activated by depletion of calcium from intracellular stores, such as the endoplasmic reticulum (ER).
- These channels open to allow calcium influx from the extracellular environment, replenishing the ER stores.

**4. Calcium release channels in the ER:**
- Include inositol trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs).
- Activated by intracellular messengers like IP3 or calcium itself, leading to the release of calcium from the ER into the cytosol.

**5. Calcium pumps:**
- Actively transport calcium ions from the cytosol back into the ER or across the plasma membrane.
- This process maintains the concentration gradient for calcium, ensuring sustained calcium signaling.

**6. Calcium-binding proteins:**
- Bind to calcium ions, acting as buffers to regulate the free calcium concentration in the cytosol.
- They can also act as sensors, triggering downstream signaling events in response to calcium changes.

**7. Calcium signaling pathways:**
- Involve a cascade of events that translate calcium signals into specific cellular responses.
- These pathways often involve protein kinases, phosphatases, and transcription factors, leading to changes in gene expression, protein activity, and cellular behavior.

**Overall, positive regulation of cytosolic calcium concentration is a highly dynamic process that is precisely controlled by a complex network of signaling pathways, molecular mechanisms, and feedback loops. This intricate regulation ensures that calcium signals are transduced into specific cellular responses, enabling proper cellular function and homeostasis.**
'"

Proteins (88)

Compounds (1,596)