Activity of the upstream <scp>TATA</scp>‐less promoter of the <i>p21</i>^{<i>Waf1/Cip1</i>} gene depends on transcription factor <scp>IIA</scp> (<scp>TFIIA</scp>) in addition to <scp>TFIIA</scp>‐reactive <scp>TBP</scp>‐like protein

<jats:sec><jats:label /><jats:p><jats:styled-content style="fixed-case">TATA</jats:styled-content>‐binding protein‐like protein (<jats:styled-content style="fixed-case">TLP</jats:styled-content>) binds to transcription factor <jats:styled-content style="fixed-case">IIA</jats:styled-content> (<jats:styled-content style="fixed-case">TFIIA</jats:styled-content>) with high affinity, although the significance of this binding is poorly understood. In this study, we investigated the role of <jats:styled-content style="fixed-case">TFIIA</jats:styled-content> in transcriptional regulation of the <jats:italic>p21</jats:italic><jats:sup><jats:italic>Waf1/Cip1</jats:italic></jats:sup> (<jats:italic>p21</jats:italic>) gene. It has been shown that <jats:styled-content style="fixed-case">TLP</jats:styled-content> is indispensable for p53‐activated transcription from an upstream <jats:styled-content style="fixed-case">TATA</jats:styled-content>‐less promoter of the <jats:italic>p21</jats:italic> gene. We found that mutant <jats:styled-content style="fixed-case">TLP</jats:styled-content>s having decreased <jats:styled-content style="fixed-case">TFIIA</jats:styled-content>‐binding ability exhibited weakened transcriptional activation function for the upstream promoter. Activity of the upstream promoter was enhanced considerably by an increased amount of <jats:styled-content style="fixed-case">TFIIA</jats:styled-content> in a p53‐dependent manner, whereas activity of the <jats:styled-content style="fixed-case">TATA</jats:styled-content>‐containing downstream promoter was enhanced only slightly. <jats:styled-content style="fixed-case">TFIIA</jats:styled-content> potentiated the upstream promoter additively with <jats:styled-content style="fixed-case">TLP</jats:styled-content>. Although <jats:styled-content style="fixed-case">TFIIA</jats:styled-content> is recruited to both promoters, activity of the upstream promoter was much more dependent on <jats:styled-content style="fixed-case">TFIIA</jats:styled-content>. Recruitment of <jats:styled-content style="fixed-case">TFIIA</jats:styled-content> and <jats:styled-content style="fixed-case">TLP</jats:styled-content> to the upstream promoter was augmented in etoposide‐treated cells, in which the amount of <jats:styled-content style="fixed-case">TFIIA</jats:styled-content>–<jats:styled-content style="fixed-case">TLP</jats:styled-content> complex is increased, and <jats:styled-content style="fixed-case">TFIIA</jats:styled-content>‐reactive <jats:styled-content style="fixed-case">TLP</jats:styled-content> was required for the recruitment of both factors. It was confirmed that etoposide‐stimulated transcription depends on <jats:styled-content style="fixed-case">TLP</jats:styled-content>. We also found that <jats:styled-content style="fixed-case">TFIIA</jats:styled-content>‐reactive <jats:styled-content style="fixed-case">TLP</jats:styled-content> acts to decrease cell growth rate, which can be explained by interaction of the <jats:italic>p21</jats:italic> promoter with the transcription factors that we examined. The results of the present study suggest that the upstream <jats:styled-content style="fixed-case">TATA</jats:styled-content>‐less promoter of <jats:italic>p21</jats:italic> needs <jats:styled-content style="fixed-case">TFIIA</jats:styled-content> and <jats:styled-content style="fixed-case">TFIIA</jats:styled-content>‐reactive <jats:styled-content style="fixed-case">TLP</jats:styled-content> for p53‐dependent transcriptional enhancement.</jats:p></jats:sec><jats:sec><jats:title>Structured digital abstract</jats:title><jats:p> <jats:list list-type="bullet"> <jats:list-item><jats:p><jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.uniprot.org/uniprot/P62340">TLP</jats:ext-link> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0914">physically interacts</jats:ext-link> with <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.uniprot.org/uniprot/P52655">TFIIA beta</jats:ext-link> and <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.uniprot.org/uniprot/P52655">TFIIA alpha</jats:ext-link> by <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0007">anti tag coimmunoprecipitation</jats:ext-link> (<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.ebi.ac.uk/intact/interaction/EBI-9524851">View interaction</jats:ext-link>)</jats:p></jats:list-item> <jats:list-item><jats:p><jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.uniprot.org/uniprot/P52655">TFIIA alpha/beta</jats:ext-link> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0915">physically interacts</jats:ext-link> with <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xl ...