Evaluation of the role of Meis 2 during inner ear formation and morphogenesis

Abstract

Meis genes are vertebrate orthologues of the Drosophila homolog homothorax (hth) gene which encode for transcription factors belonging to a subfamily of TALE proteins. In mammals, TALE superclass comprises two families: PBC (Pbx1-4 genes) and MEINOX, this latter including the PREP (Prep1-2 genes) and MEIS (Meis1-3 genes) sub-families (Schulte, 2014). TALE (Three Aminoacid Loop Extension) proteins receive their name from the shared feature of a proline-tyrosine-proline motive insertion between the first and second helix of the highly conserved helix-loop-helix homeodomain. (Longobardi et al., 2014) This homeodomain is around 60 amino acids long and allows TALE proteins to bind to DNA, thus conferring them the ability to act as transcription factors. (Mukherjee and Bürglin, 2007). Additionally, these proteins contain protein-protein interaction domains in their amino-terminal regions that permit them to form complexes with other transcription factors. While the homeodomain is conserved throughout the members of the TALE class, these amino-terminus regions are family specific: PBX family possess PBC-A and PBC-B domains while the MEIS-A and MEIS-B domains are present in the PREP and MEIS subfamilies