Cell Signaling

Autocrine signaling

Signaling between different parts of one cell; the signaling cell and the responding cell are one and the same.

Endocrine signaling

Signaling by molecules that travel through the bloodstream.

G protein-coupled receptor protein

A receptor that couples to G proteins, which bind to the guanine nucleotides GTP and GDP.

Growth factor

In animals, any one of a group of small, soluble molecules, usually the signal in paracrine signaling, that affect cell growth, cell division, and changes in gene expression.

Ion channels

Channel-like membrane proteins that open and close, thereby altering the flow of ions across the plasma membrane.

Ligand

Alternative term for a signaling molecule that binds with a receptor, usually a protein.

Paracrine signaling

Signaling by a molecule that travels a short distance to the nearest neighboring cell to bind its receptor and deliver its message.

Phosphatases

An enzyme that removes a phosphate group from another molecule.

Receptor activation

The “turning on” of a receptor, which often occurs when a signaling molecule binds to a receptor on a responding cell.

Receptor kinases

A receptor that is an enzyme that adds a phosphate group to another molecule.

Responding cell

The cell that receives information from the signaling molecule

Response

A change in cellular behavior, such as activation of enzymes or genes, following a signal.

Signaling cell

The source of a signaling molecule.

Signaling molecule

The carrier of information transmitted when the signaling molecule binds to a receptor; also referred to as a ligand.

Signal transduction

TBD

termination

In protein translation, the time at which the addition of amino acids stops and the completed polypeptide chain is released from the ribosome. In cell communication, the stopping of a signal.