Lecture12 - Lecture 12 Background reading MBOC 5th Edition...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 12 5/13/10 Background reading: MBOC 5 th Edition: Chapter 15: pages 921 - 926 MBOC 4 th Edition: Chapter 15: pages 871 – 876 Outline: Family of α subunits G S G olf G t Gq Inositol Phospholipid Pathway IP 3 Diacylglycerol Enzyme-linked receptors Receptor tyrosine kinases SH 2 and SH 3 domains
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Had been considering G protein-mediated signal transduction. The G protein is the transducer which relays the information that the signal has bound to the receptor across the membrane to the primary intracellular target. The primary target is either a protein that can change the concentration of a second messenger or that can act as an ion channel. - signal receptor transducer intracellular target
Background image of page 2
Family of α subunits ¾ 20 identified Many different receptors can interact with them Can bind to same βγ subunits. Thus, different receptors bind to selected types of α subunits and lead to different responses. Will now consider examples of signal transduction with various α subunits: G S G S subunit : acts as accelerator and activates adenylate cyclase. adenylate cyclase is thus the primary target and cyclic AMP (cAMP) is produced.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
In most animal cells cAMP exerts its effect by activating cAMP-dependent protein kinase, called protein kinase A (PKA). Ed Krebs – received Nobel prize for discovering this activation.
Background image of page 4
Substrates for PKA differ in different cell types: Skeletal muscle cells: PKA phosphorylates enzymes involved in glycogen breakdown Signal = adrenalin Receptor = β -adrenergic receptor Primary target = adenylate cyclase Effect: Activates PKA, which activates glycogen phosphorylase, which catalyzes breakdown of glycogen to glucose-1-P that enters glycolysis. Thus, get burst of energy within seconds.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 17

Lecture12 - Lecture 12 Background reading MBOC 5th Edition...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online