Cell-Cell Communication and Signaling

Receptors located inside the cell, either in the cytosol or nucleus.

Small, non-polar molecules that can easily pass through the cell membrane.

A group of hormones, including testosterone and estrogen, that can bind to intracellular receptors.

A protein that binds to specific DNA sequences and influences gene expression.

A complex formed when a hormone binds to its specific receptor protein.

A molecule that binds specifically to another molecule, usually a protein, to initiate a cellular response.

A signaling pathway that converts an extracellular signal into an intracellular response.

A protein on the cell surface that binds to a specific ligand, initiating a signal transduction pathway.

A type of cell surface receptor that has enzymatic activity and is involved in growth factor signaling.

A signaling molecule that triggers a cellular response by binding to a specific receptor.

The initial step in a signal transduction pathway where a receptor binds to a signal molecule.

The series of molecular events that amplify and relay the signal from the receptor to the target protein.

The final cellular response to the signal, such as changes in metabolism, gene expression, or cell shape.

An enzyme that breaks down cAMP (cyclic adenosine monophosphate), decreasing its concentration and terminating its signaling activity.

A series of protein phosphorylation reactions that amplify and transmit signals within a cell.

Enzymes that remove phosphate groups from proteins.

A lipid molecule that is cleaved by phospholipase C to generate two important second messengers: inositol triphosphate (IP3) and diacylglycerol (DAG).

A second messenger that binds to and opens calcium channels on the endoplasmic reticulum (ER), leading to an increase in intracellular calcium.

Different receptor proteins can bind the same signal molecule, but lead to different responses.

The process of turning off a signal transduction pathway is crucial for maintaining cellular homeostasis.

A condition where a signal transduction pathway cannot be shut off, leading to uncontrolled cellular activity.

Vibrio cholerae secretes a toxin that modifies a key protein in the signal transduction pathway, preventing its deactivation.

Drugs that block the action of neurotransmitters by competing for binding sites on receptors.

A model that explains how receptors recognize and bind specific molecules based on shape complementarity.

Genes that encode proteins involved in regulating cell growth and division; they can be transformed into oncogenes.

Genes that promote uncontrolled cell growth and division, often caused by mutations in proto-oncogenes.

A class of drugs specifically designed to target and inhibit the action of signaling proteins involved in cancer development.

Signal transduction can be categorized by the type of communication: endocrine, paracrine, synaptic, or direct cell contact.

A type of cell surface receptor that, upon binding an extracellular signal molecule, activates its intrinsic tyrosine kinase activity, leading to phosphorylation of itself and other intracellular proteins, ultimately triggering a cellular response.

The region on a receptor tyrosine kinase (RTK) where the signal molecule (ligand) binds.

The process by which two receptor tyrosine kinases (RTKs) come together to form a dimer (two-part molecule).

The addition of phosphate groups to specific tyrosine amino acids within a protein, often mediated by kinases.

Proteins that receive and relay signals within a cell, often activated by phosphorylation.

A protein that adds phosphate groups to other proteins, usually to activate them.

A type of ion channel receptor that opens in response to a specific ligand binding.

The movement of charged ions across a cell membrane through specialized protein channels.

The process of muscle contraction, often initiated by signaling pathways involving ion channels.

The process of communication between nerve cells, involving signals transmitted by ion channels.

An enzyme that cleaves phospholipids, particularly those found in cell membranes, and generates second messengers like diacylglycerol (DAG) and inositol triphosphate (IP3).

A protein that is activated by binding to GTP, a signaling molecule involved in cellular processes.

A molecule that relays signals within a cell after the initial signal molecule binds to a receptor on the cell surface.

A cyclic nucleotide that acts as a second messenger, triggering cellular responses.

An enzyme that catalyzes the conversion of ATP to cAMP, a crucial step in cAMP-mediated signaling.

A protein that phosphorylates other proteins, activating or inactivating them.

An enzyme involved in glycogen breakdown, activated by phosphorylation.

A process where a signal molecule binds to a receptor on the cell surface, initiating a cascade of events that amplify and relay the signal inside the cell.

The process by which a phosphate group is added to a protein.

The process by which a phosphate group is removed from a protein.

A molecule that initiates a cellular response, triggering a signaling cascade.

A molecule that is involved in the amplification of the signal during signal transduction.

The process by which cells respond to external signals.

A series of steps that amplify and relay the signal from the initial signal molecule to the cellular response.