How can SREBP2, a membrane-bound protein outside the nucleus be a transcription factor in the nucleus? What is it a TF for?
- processing is increased when cells have low cholesterol levels
- release of a soluble portion of the protein that then enters the nucleus to bind promoters
- high intracellular cholesterol - genes encoding LDLR and HMG-CoA reductase (that mediate uptake of LDL or control cholesterol synthesis) are not transcribed