Final answer:
The thyroid receptor is typically the transcription factor that remains bound to the promoter even when the promoter is repressed. Other steroid hormone receptors bind their hormone and interact with the DNA to regulate gene expression, but the thyroid receptor can bind to its response elements without the hormone.
Step-by-step explanation:
Steroid hormone receptors are special proteins that act as transcription factors in gene regulation. They possess binding sites for specific steroid molecules and when bound to their hormone, they can regulate the transcription of genes by binding to DNA sequences known as response elements within the promoter regions. For a steroid hormone to turn gene transcription on, the receptor must bind to the hormone and the resultant complex will interact with the DNA to modulate gene expression.
The glucocorticoid receptor is one such receptor that belongs to the nuclear receptor superfamily and it functions as a zinc-finger transcription factor. The receptor can exist in an inactive form in the cytoplasm or it may already be located in the nucleus. Upon binding its hormone, it will interact with specific response elements such as 5'-AGAACAnnnTGTTCT-3' to regulate gene transcription.
The specific question asks which transcription factor remains at the promoter even when the promoter is repressed. Although all the receptors listed have the potential to bind to the promoter, the correct answer is typically the thyroid receptor (thyroid hormone receptor), which is known to bind to its response elements in the absence of the hormone and can both repress and activate transcription depending on the presence of thyroid hormone.