Briefly, describe how GPCR and heterotrimeric G protein-mediated signaling occurs.

Briefly, describe how GPCR and heterotrimeric G protein-mediated signaling occurs.
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1 Answer

Answer :

Binding of a signaling molecule (ligand) to GPCRs causes a conformation change in
GPCR, leading to heterotrimeric G protein activation, where GTP physically replaces
the GDP bound to the alpha subunit. As a result, the G protein subunits dissociate
into two parts: the GTP-bound alpha subunit and a beta-gamma dimer. The
“activated” G protein subunits diffuse laterally and interact with other membrane
proteins, leading to the production of any number of second messengers. Note that
some G proteins stimulate the activity of target proteins, whereas others G proteins
are inhibitory.
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