What type of proteins do G-proteins primarily interact with in signal transduction?

What type of proteins do G-proteins primarily interact with in signal transduction?

• A. Receptors
• B. Ion channels
• C. Effector proteins
• D. Transcription factors

Answer: (C)

G-proteins primarily interact with effector proteins in the signal transduction pathway. When a signaling molecule, such as a hormone or neurotransmitter, binds to a G-protein-coupled receptor (GPCR) on the cell surface, it activates the associated G-protein. This activation typically leads to the exchange of GDP for GTP on the alpha subunit of the G-protein, resulting in a conformational change that allows the G-protein to dissociate into its active form. Once activated, the G-protein interacts with various effector proteins, which can include enzymes like adenylyl cyclase or phospholipase C, or ion channels. These effector proteins then propagate the signal within the cell by generating second messengers such as cyclic AMP or inositol trisphosphate, which further activate intracellular processes. This interaction is crucial for the amplification of the signal and for eliciting a cellular response to the original extracellular signal. The other types of proteins mentioned either play roles at different points in the signaling pathway or are part of downstream effects but do not directly interact with G-proteins during the initial signaling cascade. For example, receptors initiate the signaling by binding to ligands rather than interacting directly with G-pro

G-proteins primarily interact with effector proteins in the signal transduction pathway. When a signaling molecule, such as a hormone or neurotransmitter, binds to a G-protein-coupled receptor (GPCR) on the cell surface, it activates the associated G-protein. This activation typically leads to the exchange of GDP for GTP on the alpha subunit of the G-protein, resulting in a conformational change that allows the G-protein to dissociate into its active form.

Once activated, the G-protein interacts with various effector proteins, which can include enzymes like adenylyl cyclase or phospholipase C, or ion channels. These effector proteins then propagate the signal within the cell by generating second messengers such as cyclic AMP or inositol trisphosphate, which further activate intracellular processes. This interaction is crucial for the amplification of the signal and for eliciting a cellular response to the original extracellular signal.

The other types of proteins mentioned either play roles at different points in the signaling pathway or are part of downstream effects but do not directly interact with G-proteins during the initial signaling cascade. For example, receptors initiate the signaling by binding to ligands rather than interacting directly with G-pro