Final answer:
Upon binding to HSF1, the HSE becomes active, leading to the transcription of heat shock proteins, which act as molecular chaperones to protect the cell.
Step-by-step explanation:
The binding of HSF1 (Heat Shock Factor 1) to HSE (Heat Shock Element) leads to the activation of HSF1, which then upregulates the expression of heat shock proteins (HSPs). These proteins help in protecting the cell against stress by acting as molecular chaperones, ensuring proper protein folding and preventing protein aggregation. Thus, the correct answer to what happens to HSE after being bound to HSF1 is B) It becomes active. This is because the HSE-HSF1 complex promotes transcription of heat shock proteins.
The process of heat shock response can also involve other cellular activities such as phosphorylation, but the direct consequence of HSE binding HSF1 is the activation of transcription for HSPs. This does not result in degradation, phosphorylation, or export of HSE from the nucleus.