What is Autocrine, Paracrine, Juxtacrine Signaling apart from the Well known Endocrine Signaling? Biochemistry of Hormones.
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- Cells have specific response – How?
- What is the sequence of events?
To answer these questions we must go through some basics first, which are explained in the coming lessons.
Signal Transduction
Signal molecules are of different types and the process of transferring the signal into the cell is called Signal transduction.
Signal molecules can be:
- Hormones
- Drugs
- Toxins
- Chemicals
- Bacteria
- Neurotransmitters.
There are two types of cells in signal transduction:
- The sender cell where the signal originates and,
- The target cell that receives the signal.
The signal alters or modulates the activity/function of the cell
Types of Signal Transduction
- Autocrine
- Paracrine
- Juxtacrine
- Endocrine
1. Autocrine
Autocrine signaling occurs when same cell acts as sender & recipient e.g.
- Growth
- Differentiation
- Immune & inflammatory response
2. Paracrine
Paracrine signaling is affected by local mediators which have their effect near the site of secretion without entering the circulation.
The effect is rapid and transient.
Examples are:
- Prostaglandins &
- Neurotransmitters
3. Juxtacrine
Juxtacrine signaling occurs when the two types of cells are adjacent to each other so, that the contact is established through gap junctions or through protein molecules on the surface of the two cells.
4. Endocrine
Endocrine signaling is between cells which are located at a distance from each other & the signal may be:
Hormones or chemical messengers secreted into circulation.
Once they reach the target cell, they bind to specific target cell receptors with high affinity.
All these lectures are organized and listed in detail in their proper sections. To view these lessons please visit the Hormones & Signal Transduction Section. This can be approached by directly clicking the Biochemistry II button or it can also be approached from the drop down menu in Biochemistry II tab. Once you reach the section click the curriculum tab to view the full list in the section.
Any further questions or inquiries are welcome.