Question

What are the steps of Direct Gene Activation (Steroid Hormone Action)?

1) Hormone binds to a receptor in the cytoplasm
2) Hormone-receptor complex enters the nucleus
3) Hormone-receptor complex binds to specific DNA sequences
4) Transcription factors are recruited to activate gene expression
5) All of the above

Answer 1

Steroid hormone action involves the hormone binding to an intracellular receptor, forming a complex that binds to DNA to regulate gene expression, followed by the synthesis of mRNA and protein to effect cellular change.

Step-by-step explanation:

The steps of Direct Gene Activation (Steroid Hormone Action) are as follows:

1. The hormone binds to a receptor in the cytoplasm or nucleus forming a hormone-receptor complex.
2. If not already in the nucleus, the hormone-receptor complex enters the nucleus crossing the nuclear envelope.
3. The hormone-receptor complex binds to specific DNA sequences known as response elements located in the promoters of target genes.
4. Transcription factors are recruited by this complex to the promoter region, leading to the activation or repression of gene expression.
5. All of the above steps are required for the hormone to exert its regulatory effects on gene transcription.

The process begins with the steroid hormone crossing the plasma membrane to access intracellular receptors. Once the hormone binds to its receptor, it changes the shape of the receptor, which then binds to specific sequences in the DNA to modulate gene transcription. This leads to mRNA formation and eventually protein synthesis, which alters cell activity.