molecular events

Definition: A molecular event is a biochemical reaction changing a biochemical component.

Examples

 post-traductional modifications

• protein phosphorylation
• protein glycosylation
• protein farnesylation
• myristoylation
• palmitoylation

 nucleic acid methylation

Signal transduction

Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalysed by protein kinases, which ultimately results in a cellular response.

Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used.

The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a signaling cascade (or signaling pathways ), which is a chain of biochemical events forming signaling pathways.

When signaling pathways interact with one another they form molecular networks , which allow cellular responses to be coordinated, often by combinatorial signaling events.

At the molecular level, such responses include changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location.

These molecular events are the basic mechanisms controlling cell growth , cell proliferation , cell metabolism and many other cellualr processes.

In multicellular organisms, signal transduction pathways have evolved to regulate cell communication in a wide variety of ways.

See also

 membrane receptors
 signaling pathways