What is the Difference Between Cell Signalling and Signal Transduction

The main difference between cell signaling and signal transduction is that cell signaling is the cell’s ability to receive, process, and transmit signals from the environment and the cell. Meanwhile, signal transduction is the process of chemical or physical signal transmission through the cell as a series of molecular events.

Cell signaling and signal transduction are two processes by which cell signals transmit. They are essential for development, tissue repair, immunity, and homeostasis. 

Key Areas Covered

1. What is Cell Signalling
– Definition, Features, Importance
2. What is Signal Transduction
– Definition, Features, Importance
3. Similarities Between Cell Signalling and Signal Transduction
– Outline of Common Features
4. Difference Between Cell Signalling and Signal Transduction
– Comparison of Key Differences

Key Terms

Cell Signalling, Signal Transduction

What is Cell Signalling

Cell signaling is the cell’s ability to receive, process, and transmit signals from the environment and within the cell. Extracellular signals that initiate cell signaling can be either mechanical signals such as pressure, voltage, light, and temperature or chemical signals such as small molecules, peptides, and gases. Furthermore, there are six types of cell signaling mechanisms: autocrine, paracrine, juxtacrine, intracrine, or endocrine. Here, autocrine signaling involves the secretion of hormones and chemical messengers that bind to the cell leading to changes in the cell. Meanwhile, in paracrine signaling, cell signals make changes in the nearby cells. Whereas in juxtacrine signaling, a ligan in one cell binds with the receptor of the other cell.

Figure 1: Extracellular Cell Signaling Pathways

Furthermore, in intracrine signaling, the cell stimulates itself by producing a factor that acts within the cell. And in endocrine signaling, hormones released by internal glands transmit through the circulatory system regulating a distant target organ. Apart from these, cell signaling is vital for development, tissue repair, immunity, and homeostasis.

What is Signal Transduction

Signal transduction is the process by which chemical and physical signals transmit through cells in a series of molecular events. There, protein phosphorylation is the main method of signal transduction by protein kinases. Also, proteins that detect the stimuli are called receptors. Ligand binding to the receptor results in a biochemical cascade with events known as signaling pathways. At the molecular level, signal transduction makes changes in the transcription and translation of genes, post-translational and conformational changes in proteins, and the location of proteins. These molecular events are important in cell growth, proliferation, and metabolism.

Figure 2: Signal Transduction Pathway

Moreover, ligands are the first messengers that bind to the receptors or the signal transducers and activate primary effectors. Primary effectors are linked to the second messenger that activates second effectors.

Similarities Between Cell Signalling and Signal Transduction

• Cell signaling and signal transduction are two processes by which cells transmit signals that are required for their growth and development.
• They are also important for tissue repair, immunity, and homeostasis.
• They activate ion channels initiating a second messenger system.

Difference Between Cell Signalling and Signal Transduction

Definition

Cell signaling refers to the process by which a cell responds to substances outside the cell through signaling molecules found on the surface of and inside the cell, while signal transduction refers to the process of transferring a signal throughout an organism.

Significance

Cell signaling is the ability of the cell to receive, process, and transmit signals from the environment and from the cell, while signal transduction is the process of chemical or physical signal transmission through the cell as a series of molecular events.

Importance

Cell signaling is important for development, tissue repair, immunity, and homeostasis, while signal transduction is important for cell growth, proliferation, and metabolism.

Conclusion

In brief, cell signaling and signal transduction are two types of signal-transmitting processes important in different cellular processes. Cell signaling is the cell’s ability to receive, process, and transmit signals from the environment. Also, it is important for development, tissue repair, immunity, and homeostasis. In comparison, signal transduction is the process of chemical and physical signals transmitted through the cell. It is important for growth, proliferation, and metabolism. Therefore, the main difference between cell signaling and signal transduction is their significance.

References:

1. Khan Academy. (n.d.-a). Introduction to cell signaling (article). Khan Academy. 

Image Courtesy:

1. “Cell signalling” By Doublethink – Own work (Public Domain) via Commons Wikimedia
2. “Signal transduction pathways” By cybertory – Own Work (CC-BY SA 3.0) via Commons Wikimedia