One of your homework questions is reproduced below. All six answers were correct. Can you
think of two more conceivable answers to the question below?
Many promoters are regulated by proteins that bind to adjacent DNA sequences. Which of the following is correct?
A. Some transcriptional regulators stimulate transcription and do so only when binding a low molecular weight ligand.
B. Some transcriptional regulators stimulate transcription and do so only when NOT binding a low molecular weight ligand.
C. Some transcriptional regulators inhibit transcription and do so only when binding a low molecular weight ligand.
D. Some transcriptional regulators inhibit transcription and do so only when NOT binding a low molecular weight ligand.
E. Some transcriptional regulators stimulate transcription and do so only when phosphorylated.
F. Some transcriptional regulators repress transcription and do so only when phosphorylated.

It’s not multiple choice, I need help coming up with two more answers that are true

Phosphorylation activation:

1- p53 (transcriptional activator)

2- CDK8-cyclin C (transcriptional inhibitor)

Explanation:

Phosphorylation is a well-studied post-translational modification mediated by a protein called 'kinases' which phosphorylates specific protein substrates. This post-translational modification (phosphorylation) acts as a reversible switch capable of modulating protein function. Phosphorylation at specific amino acid residues (e.g., tyrosine, serine) controls protein function by triggering conformational changes in the phosphorylated protein. For example, P53 is a transcription activator activated by phosphorylation at multiple sites in its N-terminal region. P53 activates transcription of different genes by modulating protein-protein interactions with different substrates (e.g., MDM-2, CBP/p300, TFII). On the other hand, cyclins are proteins that have no enzymatic activity but are able to activate cyclin-dependent kinases (CDKs) by binding to them. CDK8-cyclin C (SRB10-SRB11) is a negative regulator of transcription that is able to inhibit transcription by phosphorylating the carboxy-terminal domain of the largest subunit of RNA polymerase II (Pol II) before the formation of the preinitiation transcriptional complex.