Chapter15Pt2

Protein-tyrosine phosphorylation

A mechanism for signal transduction that involves the addition of a phosphate group to a tyrosine residue on a protein.

Ras-MAP kinase pathway

A well-characterized signaling cascade involved in regulating cell division, differentiation, and other vital cellular processes.

Calcium as a secondary messenger

Calcium ions that play a crucial role in cellular processes, serving as a signaling molecule in response to various stimuli.

Convergence in signaling pathways

The process where signals from unrelated receptors activate a common effector.

Divergence in signaling pathways

The phenomenon where a single signal leads to the activation of multiple effectors.

Cross-talk in signaling pathways

The interaction between different signaling pathways, allowing signals to influence each other.

Apoptosis

Programmed cell death characterized by cell shrinkage, loss of adhesion, chromatin dissection, and engulfment by phagocytes.

Necroptosis

A form of programmed cell death that results in the rupture of the plasma membrane and often triggers inflammation.

Insulin receptor

A receptor that mediates the effects of insulin by regulating glucose uptake and metabolism.

SH2 domain

A protein domain that binds to phosphorylated tyrosines, playing a key role in signaling pathways.

Autophosphorylation

The process where a kinase adds phosphate groups to itself, which is crucial for activation in signaling.

PI 3-kinase (PI3K)

An enzyme involved in signaling pathways that influence cell growth, proliferation, and metabolism.

Calmodulin

A calcium-binding protein that mediates various cellular responses through calcium ion binding.

GTPase-activating proteins (GAPs)

Proteins that accelerate the hydrolysis of GTP to GDP, thus inactivating GTP-binding proteins like Ras.

Guanine nucleotide-exchange factors (GEFs)

Proteins that promote the exchange of GDP for GTP, activating GTP-binding proteins.

Caspases

Proteolytic enzymes that play essential roles in apoptosis, cleaving specific proteins to execute cell death.

Receptor tyrosine kinase (RTK)

A type of cell-surface receptor that, upon ligand binding, activates its intrinsic tyrosine kinase activity.

Cytosolic calcium concentration

The level of calcium ions in the cytosol, which is carefully regulated for cellular function.

Phospholipase C

An enzyme that generates inositol trisphosphate (IP3) and diacylglycerol (DAG), linked to calcium signaling.

Store-operated calcium entry (SOCE)

A process by which depleted calcium levels in the endoplasmic reticulum trigger the opening of calcium channels in the plasma membrane.