signaling

Definition

Target type: biologicalprocess

The entirety of a process in which information is transmitted within a biological system. This process begins with an active signal and ends when a cellular response has been triggered. [GOC:mtg_signal, GOC:mtg_signaling_feb11, GOC:signaling]

Signaling is a fundamental biological process that allows cells to communicate with each other and their environment. It involves the transmission of information from one cell to another, or from one part of a cell to another. This communication is essential for coordinating cellular activities, such as growth, development, metabolism, and response to stimuli. Signaling pathways are intricate networks of interacting molecules that relay signals from the outside world to the inside of cells. These pathways involve a series of events that begin with the binding of a signaling molecule, known as a ligand, to a specific receptor protein on the cell surface or inside the cell. This binding initiates a cascade of events that ultimately results in a cellular response. There are different types of signaling pathways, each with its own specific mechanism and function. Some common types include:

1. **Autocrine signaling:** A cell signals itself.
2. **Paracrine signaling:** A cell signals a nearby cell.
3. **Juxtacrine signaling:** A cell signals a directly adjacent cell.
4. **Endocrine signaling:** A cell signals a distant cell through the bloodstream.
5. **Synaptic signaling:** A specialized type of paracrine signaling that occurs between neurons.

Each signaling pathway involves a series of steps that can be summarized as follows:

**1. Reception:** The signaling molecule binds to a specific receptor protein on the cell surface or inside the cell.
**2. Transduction:** The binding of the ligand to the receptor initiates a cascade of events that transduce the signal from the outside of the cell to the inside. This typically involves a series of protein interactions and modifications.
**3. Signal amplification:** The signal is amplified as it is passed down the signaling pathway, allowing a small number of signaling molecules to trigger a large cellular response.
**4. Response:** The signal ultimately reaches its target, which may be a gene, an enzyme, or another protein. This results in a specific cellular response, such as changes in gene expression, protein activity, or cellular behavior.

**Signaling pathways are highly regulated and can be influenced by a variety of factors, including:**

* **The concentration of signaling molecules**
* **The availability of receptors**
* **The activity of signaling proteins**
* **The presence of other signaling pathways**

**Dysregulation of signaling pathways can lead to a variety of diseases, including cancer, diabetes, and neurodegenerative disorders. Therefore, understanding signaling pathways is crucial for developing new therapies for these diseases.**'
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Proteins (1)

Compounds (23)