Which one of the following is the example of ATP-binding cassette (ABC) transpoer?
**Core Concept**
The ATP-binding cassette (ABC) transporters are a family of transmembrane proteins that utilize the energy from ATP hydrolysis to transport a wide range of substrates across cell membranes. They play a crucial role in various cellular processes, including drug efflux, detoxification, and nutrient uptake.
**Why the Correct Answer is Right**
P-glycoprotein (P-gp), also known as multidrug resistance protein 1 (MDR1), is an example of an ABC transporter. It is encoded by the ABCB1 gene and is primarily expressed in the plasma membrane of various cells, including epithelial cells, neurons, and immune cells. P-gp functions as an efflux pump, using the energy from ATP hydrolysis to transport a broad range of substrates, including drugs, out of the cell. This mechanism contributes to multidrug resistance in cancer cells and can also influence the pharmacokinetics of various medications.
**Why Each Wrong Option is Incorrect**
**Option A:** Not a specific example of an ABC transporter.
**Option B:** Not a well-known ABC transporter; may be a distractor for a less familiar option.
**Option C:** Not an ABC transporter; may be a distractor for a non-ABC transporter mechanism.
**Clinical Pearl / High-Yield Fact**
ABC transporters, like P-gp, can significantly impact the efficacy and toxicity of various medications by influencing their pharmacokinetics. Understanding the role of ABC transporters is essential for optimizing drug therapy and predicting potential drug interactions.
**Correct Answer: C. P-glycoprotein (P-gp)**