Transcription factors are proteins that play a key role in the regulation of gene expression in all living organisms. In plants, the HD-Zip family of transcription factors is composed of proteins which possess a homeodomain DNA-binding domain associated to a leucine-zipper dimerization domain. The presence of other motifs and domains allows the further classification of these proteins in four subfamilies, I to IV. Studied members from subfamily I bind in vitro the same pseudopalindromic sequence and among them, several exhibit similar expression patterns. However, most experiments in which HD-Zip I proteins were overexpressed under the control of the constitutive promoter 35S CaMV resulted in transgenic plants with clearly different phenotypes.
Aiming to further investigate the structural mechanisms underlying these observations, phylogenetic and sequence analyses were performed on HD-Zip I proteins from a wide range of plants species. Subgroups of proteins with previously uncharacterized conserved motifs were identified and these motifs were associated in silico with transactivation and post-translational modifications. Experiments in yeast and in planta allowed us to verify some of these predictions.
From a broader perspective, these results exemplify one of the multiple sources of functional diversity within a gene family; which in plants, and specially for transcription factor families, have experienced a significant expansion.

Das Seminar "Sources of functional diversity within subfamily I HD-Zip transcription factors" von Agustin Lucas Arce findet am Dienstag, dem 08.07.2014, ab 16.00 Uhr im Hörsaal des Institute for Evolution and Biodiversity (IEB) in der Hüfferstraße 1 in Münster statt. Alle Interessierten sind herzlich willkommen.

IEB-Website: https://www.uni-muenster.de/Evolution/index.shtml