Cell signalling

A form of cell communication where a signal is sent from one cell to another through the secretion of messenger molecules that travel short distances. An example of this is growth factors, which stimulate local cells to grow and divide.

A long-distance form of cell signaling where specialized cells release hormones that travel through the circulatory system to reach target cells.

A type of cell signaling where cells communicate directly through contact, without the need for secreted signaling molecules.

Cellular proteins that bind specifically to signaling molecules (ligands) and initiate a cellular response. They are often located either on the cell surface or within the cytoplasm.

The process by which a cell converts an extracellular signal into an intracellular response.

A class of membrane receptors that attach phosphate groups to tyrosine amino acids. They can activate multiple signal transduction pathways simultaneously, allowing for complex and coordinated cellular responses.

A large family of cell-surface receptors that associate with G proteins. They bind a diverse range of signaling molecules, including neurotransmitters and hormones.

A type of membrane receptors that allow the passage of ions across the cell membrane in response to a specific signal. They play a crucial role in processes such as nerve impulse transmission.

A type of membrane receptor that acts as a gate, opening only when a specific ligand binds. This change allows specific ions to flow, affecting the cell's activity.

Proteins located in the cytoplasm or nucleus that bind to small, hydrophobic messengers like steroid and thyroid hormones. This allows these messengers to cross the membrane and activate the receptor.

A widespread cellular method for regulating protein activity. Protein kinases add phosphates to proteins from ATP, while phosphatases remove phosphates.

Small, non-protein molecules or ions that spread by diffusion and participate in signaling pathways. Examples include cAMP and calcium ions.

A type of second messenger that activates protein kinase A. It is produced by adenylyl cyclase converting ATP to cAMP.

Another common second messenger that often increases in concentration due to external signals. Its increase can trigger various cellular responses including muscle contraction, secretion, and cell division.

The final response of a cell to a signal. This response can occur in the cytoplasm or the nucleus, affecting enzyme activity, opening of ion channels, or gene expression.

A signaling pathway that regulates the synthesis of enzymes or other proteins by turning genes on or off in the nucleus. Activated receptors can act as transcription factors.

The process of stopping a signal transduction pathway. This is crucial to prevent overstimulation and ensure cell function. Inactivation mechanisms are just as important as activation.