Question

You are studying a transcriptional activator protein called CYK1, which activates cytokine genes in immune cells and has both a nuclear localization and a nuclear export signal and is normally found both in the nucleus and in the cytosol at comparable concentrations. CYK1 has a high-affinity binding partner in the nucleus (the binding partner is restricted to the nucleus). Upon activation of a certain signaling pathway, the binding protein partner is tagged for degradation. Explain the outcome of activation of the signaling pathway on cytokine gene expression and the localization of the transcriptional activator.

Answer 1

In case of degradation of binding partner, there will be decreased expression of cytokine gene along with this more CYK1 transcriptional activator will be present in cytosol.

Explanation

CYK1 Is a transcriptional activator, which activate cytokine signaling and cause secretion of cytokine .

Fir this process, transcriptional activator CYK1 must bond with its binding partner in the nucleus. This binding cause retention of CYK1 in to nucleus and its binding to response element in DNA , which later stimulate cytokine gene expression. So this binding partner must be present, in order to retain CYK1 in the nucleus as well for binding at DNA and for expression of cytokine Gene's.

So if upon activation a certain signaling pathway, the binding protein partner is tagged for degradation. Then there will be no binding partner of CYK1 in the nucleus. So there will be less CYK1 retained in the nucleus and there will be no binding of CYK1 at the DNA response element and decrease expression of cytokine gene . Which lead to decreased secretion of cytokines .