What are the two major mechanisms through which cell signaling leads to a change in cell behavior?

Question

What are the two major mechanisms through which cell signaling leads to a change in cell behavior?

Answer 1

There are two main ways that a signaling molecule can change a cell’s behavior:

1. Altering protein activity – Some signals trigger very fast responses by activating or deactivating proteins that already exist inside the cell. This usually involves phosphorylation or other chemical modifications that quickly switch enzymes or other proteins on or off.
2. Altering gene expression – Other signals work by turning specific genes on or off. This leads to changes in which proteins the cell makes, so the response takes longer but can create more long-term effects.

Most signaling pathways use one or both of these approaches to produce the final change in cell behavior.

Answer 2

Cell signaling can lead to many cellular responses. One common result of signal transduction is the activation of transcription factors leading to gene expression. Another common outcome of signaling includes stimulating metabolic pathways or the cell cycle. Other cellular responses include triggering apoptosis, cell migration, and endocytosis (ie. phagocytosis).