Download g-protein-coupled-receptor-presentation

G-PROTEIN COUPLED
RECEPTOR
REBECCA BEBE, JORDAN BELGRVE,
ALEXIS CAREY, TAMARA DUNFORD,
HASAN STOCKTON, JESSICA VASON,
ETURNITEE WALKER
G-PROTEIN COUPLED RECEPTOR
• Found only in Eukaryotes
• Largest known class of membrane receptors
• Humans have over 1,000
• Each one has a specific function
KEY NOTES
• Has 7 transmembrane α-helixes-spans the membrane 7 times
• All associated G-proteins are have three subunits
• Subunits making up the G- protein include:
•
α-subunit (attatched to membrane)
•
β-subunit
•
γ-subunit (attached to membrane)
• When inactive: GDP is bound to the alpha subunit
• When active: GTP is bound to the alpha subunit
FUNCTION OF GPCR
• Ligand shape is complementary to that of the GPCR for binding
• When bound together GPCR changes conformation
• α-subunit exchanges GDP for GTP
• α-subunit separates from β-subunit and γ-subunit (dimer)
• α-subunit regulates function of target protein
• Target protein sends signal
FUNCTION OF TARGET PROTEIN
• Target protein converts ATP to cAMP
• cAMP sends signal to other cells
• Process breaks gown glycogen forming glucose
AFTER THE SIGNAL HAS BEEN SENT
• GTP is hydrolyzed to GDP
• Subunits recombine
• GCPR looses ligand and returns to original conformation