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Explain the process of how G protein-coupled receptors (GPCRs) become activated and signal inside the cell.
Explain the process of how G protein-coupled receptors (GPCRs) become activated and signal inside the cell.
When a GPCR encounters an activated receptor, the α subunit exchanges GDP for GTP, dissociates from the β and γ subunits, and becomes active. This activation triggers intracellular signaling.
Where are the receptors for polar signaling molecules such as neurotransmitters and growth factors located? And where are the receptors for nonpolar signaling molecules such as steroid hormones located?
Where are the receptors for polar signaling molecules such as neurotransmitters and growth factors located? And where are the receptors for nonpolar signaling molecules such as steroid hormones located?
Receptors for polar signaling molecules are located on the plasma membrane, while receptors for nonpolar signaling molecules, such as steroid hormones, are located in the cytosol or in the nucleus.
What are G proteins composed of and how do they become active?
What are G proteins composed of and how do they become active?
Heterotrimeric G proteins are composed of three subunits, denoted α, β, and γ. G proteins become active when the α subunit exchanges GDP for GTP.
How are G protein signals amplified in the cytosol?
How are G protein signals amplified in the cytosol?
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What does the cellular response depend on in terms of signaling pathways?
What does the cellular response depend on in terms of signaling pathways?
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