Week 6 - Cell Signaling Flashcards
(26 cards)
Cell Signaling
The process by which cells communicate. It is essential for growth responses, immune responses, and maintains homeostasis.
Reception
Stage 1 of cell signaling; a cell detects a signaling molecule (ligand) through a receptor.
Transduction
Stage 2 of cell signaling; the signal is relayed and amplified through intracellular molecules.
Response
Stage 3 of cell signaling; the cells comes out of a specific action, like gene expression or enzyme activation.
Autocrine Signaling
Self-signaling; a cell releases a signal that binds to its own receptors or receptors on nearby identical cells. It is seen in immune cells, development, and cancer progression.
Paracrine Signaling
Local signaling; a cell secretes signaling molecules that diffuse through extracellular fluid to act on nearby target cells. It is important in local tissue coordination, inflammation, and embryonic development.
Endocrine Signaling
Long-distance signaling; hormones are released by endocrine glands into the bloodstream and travel long distances to target cells. It regulates body-wide processes like metabolism, growth, and reproduction.
Juxtacrine Signaling
Cell-to-cell contact; cells must be in direct physical contact through membrane-bound proteins. It is important in tissue development and immune responses.
GPCR Signaling
Transmembrane receptors that activate intracellular G proteins when a ligand binds. The activated G proteins trigger intracellular messengers like CAMP, IPB, DAG, to produce a response
Phosphoprylation
The process of adding a phosphate group to a protein/molecule, usually by an enzyme called a kinase, this activates or deactivates proteins.
Kinases
It is an enzyme that adds phosphate groups; a key player in phosphorylation.
Phosphatases
It is an enzyme that removes phosphate groups, turning signals off; a key player in phosphorylation.
ATP
The phosphate donor; a key player in phosphorylation. ATP -> ADP + Pi
RTK Signaling
Special case of cell surface receptors that activates intracellular pathways through phosphorylation. It regulates growth, survival, and differentiation.
Ligand Binding
The first step of RTK signaling. A signaling molecule binds to the extracellular domain of an RTK.
Dimerization
The second step of RTK signaling. 2 RTK molecules come together.
Autophosphorylation
The third stage of RTK signaling. RTK’s phosphorylate each other’s tyrosine residue on intracellular domain.
Signal Propagation
The fourth stage of RTK signaling. Phosphorylated tyrosines act as docking sites for intracellular proteins., triggering downstream signaling casades.
Cellular Response
The fifth and last stage of RTK signaling. Leads to change in gene expression, cell growth, survival, and metabolism.
Ligand-Gated Ion Channel Signaling
Ion channels open or close in response to ligand binding, allowing ions to flow in. It is used in neuronal and muscle signaling.
Intracellular Receptor Signaling.
Steroid hormone signaling; hydrophobic molecules like steroid hormones cross the plasma membrane and bind to intracellular receptors in the cytoplasm or nucleus. The receptor-ligand complex then directly regulates gene expression.
Contact Signaling
Requires cells to be in direct mem-mem contact
Gap Junction
Contact signaling that allows cell-cell transfer to ions.
Tight Junctions
Contact signaling that are an adhesion complex, makes tight seal.
