Cell Communication III

G-protein linked receptor

The structure of an inactive G-protein

Without signaling molecule G-protein is inactive

G-protein binds to receptor when signaling molecule is present

G-protein accepts GTP and disassemble into two active subunits

The α subunit of the G-protein can be deactivated through hydrolysis of GTP

Deactivation of G-protein

Reassembly of α subunit with other 2 subunits reforms inactive G-protein complex

Arrestin binds phosphorylated G-protein receptor and deactivates the receptor and

prepares it for endocytosis

Activation of gene transcription by cAMP

Synthesis and degradation of cyclic AMP

Activation of cAMP dependent protein kinase

Activation of gene transcription by cAMP

Ca2+ and diacylglycerol activate protein kinase C

Fertilization of an egg by a sperm triggers an increase in cytosolic Ca 2+

Ways in which a cell maintains a low Ca 2+ concentration in the cytosol

Ways in which a cell maintains a low Ca 2+ concentration in the cytosol

When receptor chains crosslink the receptor is phosphorylated and activated

Human growth hormone bound to its receptor tyrosine kinase

Activated receptor kinase binds intracellular signaling proteins

Ras is activated by tyrosine kinase

The Jak-STAT signaling pathway provides a fast track to the nucleus

The Jak-STAT signaling pathway provides a fast track to the nucleus