Insulin, Glucagon, and Epinephrine Signaling

Flashcards summarizing the key concepts of insulin, glucagon, and epinephrine signaling as detailed in the lecture notes.

What type of receptor does insulin bind to?

Insulin binds to a receptor tyrosine kinase.

Which receptors do epinephrine and glucagon primarily bind to?

Epinephrine and glucagon primarily bind G protein coupled receptors.

What is the effect of insulin binding to its receptor?

Insulin binding causes dimerization and auto-phosphorylation of tyrosine residues.

What role do phosphorylated tyrosines on the insulin receptor play?

They serve as docking stations for adapter proteins like insulin receptor substrate.

What kinase is activated by the insulin signaling cascade?

Insulin signaling activates the downstream kinase PDK1.

How does insulin signaling influence cellular responses?

By changing the phosphorylation state of proteins, influencing enzyme activity, gene transcription, and cell growth.

What is the role of cyclic AMP in G alpha S signaling?

Cyclic AMP activates protein kinase A, leading to phosphorylation of various proteins.

What is the function of phospholipase C in GQ signaling?

It cleaves PIP2 into inositol triphosphate (IP3) and diacylglycerol (DAG), acting as second messengers.

What effect does diacylglycerol have in signaling?

Diacylglycerol activates protein kinase C.

What occurs to IP3 after it is generated in the signaling cascade?

IP3 enhances calcium release from the endoplasmic reticulum.

What is the significance of phosphodiesterase in cyclic AMP signaling?

Phosphodiesterase degrades cyclic AMP, thus terminating the signaling.

How does cyclic AMP regulate transcription?

By binding to CREB, which then binds to the DNA enhancer element CRE to modulate transcription.