The universal nine-amino-acid transactivation domains (9aaTADs) have been identified in numerous transcription activators. Here, we identified the conserved 9aaTAD motif in all nine members of the specificity protein (SP) family. Previously, the Sp1 transcription factor has been defined as a glutamine-rich activator. We showed by amino acid substitutions that the glutamine residues are completely dispensable for 9aaTAD function and are not conserved in the SP family. We described the origin and evolutionary history of 9aaTADs. The 9aaTADs of the ancestral Sp2 gene became inactivated in early chordates. We next discovered that an accumulation of valines in 9aaTADs inactivated their transactivation function and enabled their strict conservation during evolution. Subsequently, in chordates, Sp2 has duplicated and created new paralogs, Sp1, Sp3, and Sp4 (the SP1-4 clade). During chordate evolution, the dormancy of the Sp2 activation domain lasted over 100 million years. The dormant but still intact ancestral Sp2 activation domains allowed diversification of the SP1-4 clade into activators and repressors. By valine substitution in the 9aaTADs, Sp1 and Sp3 regained their original activator function found in ancestral lower metazoan sea sponges. Therefore, the vertebrate SP1-4 clade could include both repressors and activators. Furthermore, we identified secondary 9aaTADs in Sp2 introns present from fish to primates, including humans. In the gibbon genome, introns containing 9aaTADs were used as exons, which turned the Sp2 gene into an activator. Similarly, we identified introns containing 9aaTADs used conditionally as exons in the (SP family-unrelated) transcription factor SREBP1, suggesting that the intron-9aaTAD reservoir is a general phenomenon.

• Klíčová slova
• CBP, E2A, Gal4, Gcn4, KIX, KLF, MED15, MLL, Met4, TAF9, WT1, p53,
• MeSH
• aktivace transkripce MeSH
• duplikace genu MeSH
• fylogeneze MeSH
• introny genetika   MeSH
• lidé MeSH
• molekulární evoluce * MeSH
• regulace genové exprese * MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie MeSH
• transkripční faktor Sp2 antagonisté a inhibitory   genetika   metabolismus   MeSH
• valin genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• transkripční faktor Sp2 MeSH
• valin MeSH

The Gal4 protein is a well-known prototypic acidic activator that has multiple activation domains. We have previously identified a new activation domain called the nine amino acid transactivation domain (9aaTAD) in Gal4 protein. The family of the 9aaTAD activators currently comprises over 40 members including p53, MLL, E2A and other members of the Gal4 family; Oaf1, Pip2, Pdr1 and Pdr3. In this study, we revised function of all reported Gal4 activation domains. Surprisingly, we found that beside of the activation domain 9aaTAD none of the previously reported activation domains had considerable transactivation potential and were not involved in the activation of transcription. Our results demonstrated that the 9aaTAD domain is the only decisive activation domain in the Gal4 protein. We found that the artificial peptides included in the original Gal4 constructs were results of an unintended consequence of cloning that were responsible for the artificial transcriptional activity. Importantly, the activation domain 9aaTAD, which is the exclusive activation domain in Gal4, is also the central part of a conserved sequence recognized by the inhibitory protein Gal80. We propose a revision of the Gal4 regulation, in which the activation domain 9aaTAD is directly linked to both activation function and Gal80 mediated inhibition.

• MeSH
• aktivace transkripce genetika   fyziologie   MeSH
• DNA vazebné proteiny chemie   genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• proteinové domény MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• transkripční faktory chemie   genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• GAL4 protein, S cerevisiae MeSH Prohlížeč
• Saccharomyces cerevisiae - proteiny MeSH
• transkripční faktory MeSH

The family of the Nine amino acid Transactivation Domain, 9aaTAD family, comprises currently over 40 members. The 9aaTAD domains are universally recognized by the transcriptional machinery from yeast to man. We had identified the 9aaTAD domains in the p53, Msn2, Pdr1 and B42 activators by our prediction algorithm. In this study, their competence to activate transcription as small peptides was proven. Not surprisingly, we elicited immense 9aaTAD divergence in hundreds of identified orthologs and numerous examples of the 9aaTAD species' convergence. We found unforeseen similarity of the mammalian p53 with yeast Gal4 9aaTAD domains. Furthermore, we identified artificial 9aaTAD domains generated accidentally by others. From an evolutionary perspective, the observed easiness to generate 9aaTAD transactivation domains indicates the natural advantage for spontaneous generation of transcription factors from DNA binding precursors.

• MeSH
• aktivace transkripce * MeSH
• DNA vazebné proteiny chemie   MeSH
• nádorový supresorový protein p53 genetika   MeSH
• Saccharomyces cerevisiae - proteiny chemie   MeSH
• Saccharomyces cerevisiae genetika   MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• transkripční faktory chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• GAL4 protein, S cerevisiae MeSH Prohlížeč
• nádorový supresorový protein p53 MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• transkripční faktory MeSH