Signal Transduction and Cell Signaling Review

These flashcards cover key vocabulary and concepts related to signal transduction and cell signaling based on the lecture notes provided.

Signal Transduction

The process by which a cell responds to signals from its environment through receptor activation and subsequent cellular responses.

GPCR

G Protein-Coupled Receptors, a large family of cell surface receptors that respond to various external signals.

Second Messenger

Small molecules that relay signals received at receptors on the cell surface to target molecules inside the cell.

Inositol Triphosphate (IP3)

A second messenger that triggers the release of calcium ions from the endoplasmic reticulum.

Diacylglycerol (DAG)

A second messenger that activates protein kinase C (PKC) in signaling pathways.

Calcium Ions (Ca2+)

An important second messenger in cellular signaling, involved in various physiological processes.

Phosphatidylinositol (PI)

A lipid that can be phosphorylated to produce inositol phosphates and diacylglycerol, key components in signal transduction.

Phospholipase C (PLC)

An enzyme that cleaves phosphatidylinositol (PIP2) to produce IP3 and DAG.

Ras/MAP Kinase Pathway

A signaling pathway involved in cell growth and differentiation, activated by receptor tyrosine kinases.

Adenylyl Cyclase

An enzyme that converts ATP to cyclic AMP, a key second messenger in many signaling pathways.

Transcription Factors

Proteins that help initiate or regulate the transcription of specific genes.

GTPase

An enzyme that hydrolyzes GTP to GDP, crucial for signal transduction activity of small G proteins like Ras.

Receptor Tyrosine Kinase (RTK)

A type of receptor that, upon binding a ligand, activates its intrinsic kinase activity, leading to phosphorylation of tyrosine residues.

Cytokine Receptors

Cell surface receptors that bind cytokines and activate associated kinases to initiate signaling pathways.

No Pathway

A signaling pathway involving nitric oxide that mediates muscle relaxation and vasodilation.

Phosphorylation

The addition of a phosphate group to a molecule, often used to regulate protein function.

GAPs

GTPase-activating proteins that stimulate the GTPase activity of Ras, turning it off.

GEFs

Guanine nucleotide exchange factors that facilitate the activation of Ras by promoting GDP release.

Calmodulin

A calcium-binding protein that mediates various cellular activities in response to fluctuating intracellular calcium levels.

Scaffold Proteins

Proteins that organize signaling molecules into specific complexes, enhancing the specificity and efficiency of signaling.

JAK/STAT Pathway

A signaling pathway activated by cytokine receptors, leading to activation of STAT transcription factors.

Calcium-Dependent Kinases

Enzymes that require calcium ions for their activity, often involved in signaling cascades.

Cyclic AMP (cAMP)

A second messenger generated from ATP by adenylyl cyclase, involved in various signaling pathways.

SHP1

A phosphotyrosine phosphatase that terminates signaling by dephosphorylating activated proteins.

SOCS Proteins

Suppressors of Cytokine Signaling that negatively regulate cytokine receptor signaling pathways.

IP3-Gated Channels

Channels in the endoplasmic reticulum that open in response to IP3, allowing Ca2+ release into the cytoplasm.

Trans-autophosphorylation

A process where activated receptors phosphorylate each other on tyrosine residues to propagate a signal.

SH2 Domain

A protein domain that recognizes and binds to phosphorylated tyrosines on target proteins.

Adaptors

Proteins that connect signaling components to facilitate signal transduction.

Phosphoinositides

Phosphorylated forms of phosphatidylinositol that are precursors to second messengers.

TGF-β

Transforming Growth Factor Beta, involved in regulating cellular processes like growth and differentiation.

MAP Kinase

Mitogen-Activated Protein Kinase, involved in transmitting signals from cell surface receptors to the nucleus.

Calcium-ATPases

Enzymes that pump calcium ions into the endoplasmic reticulum to maintain low cytosolic calcium levels.

Transcriptional Co-activators

Proteins that enhance the transcription of specific genes by interacting with transcription factors.