Final answer:
Nuclear receptors are proteins that function as receptors for small, hydrophobic molecules, such as steroid hormones. They are located in the cytoplasm and translocate to the nucleus upon hormone binding. In the nucleus, they bind to DNA and trigger gene transcription.
Step-by-step explanation:
Nuclear receptors are a type of proteins that function as receptors for small, hydrophobic molecules such as steroid hormones. They are typically located in the cytoplasm and bound to a heat shock protein. When a hormone binds to a nuclear receptor, it dissociates from the heat shock protein and translocates to the nucleus. In the nucleus, the hormone-receptor complex binds to a DNA sequence called a hormone response element, triggering gene transcription and translation.
Nuclear receptors have different functional domains, including the DNA-binding domain, the hormone-binding domain, and the activation domain. They act as hormone-activated transcription factors, modulating gene expression. They are involved in various biological processes and play a crucial role in the regulation of cell function and development.