You Are Interested in Studying the Transcriptional Regulation of the Gip1

Essay

You are interested in studying the transcriptional regulation of the Gip1 promoter.The Gip1 promoter contains a binding site for the Jk8 protein that overlaps with the binding site for the Pa5 protein.Jk8 and Pa5 cannot bind DNA at the same time, but both proteins are present at high levels in adult liver cells.The binding sites for Jk8 and Pa5 are shown in Figure 8-24.
Figure 8-24
Jk8 binds to site A while Pa5 binds to site B.You create mutations that remove the nonoverlapping sequences of either binding site A or B, and examine Gip1 mRNA production in adult liver cells that contain these mutations.The data you obtain from these experiments are shown in Table 8-24. $\begin{array}{c}\begin{array}{c} \text {experiment}\\ \text { number}\\\hline 1 \\ \hline 2 \\ \hline 3 \\ \hline 4\end{array}\begin{array}{cc}\text { binding site } \\\text { A } \quad \text { B } \\\hline+ \quad + \\\hline+ \quad - \\\hline- \quad + \\\hline -\quad - \end{array}\begin{array}{c}\text {Gip1 mRNA }\\\text {levels}\\\hline\text {high}\\\hline\text {hight}\\\hline\text {none}\\\hline\text {none} \end{array} \end{array}$

Table 8-24
Which transcription regulatory protein is bound in experiment #1 (the normal situation)? Explain.