How do duplicated transcription factors, which are initially identical in sequence, specialize to perform diverse functions? We have team up with the group of Susana de la Luna, at the Center for Genomic Regulation (CRG), to try to answer this question from a new perspective.
We have focused on low-complexity regions (LCRs), such as alanine or glutamine repeat expansions, because they can accumulate rapidly during evolution and may result in changes in protein-protein interactions. By studying 237 gene families originated during the two rounds of whole genome duplication at the basis of the vertebrates we have found that duplicated gene copies have acquired many more LCRs than single copy genes evolved during the same period of time. By performing experiments in two different gene families (PHOX2A/B and LHX2/9) we have shown that the gain of novel alanine-rich LCRs can increase 3-4 fold the capacity of the protein to activate transcription. The study highlights the importance of LCRs in mediating the functional diversification of duplication transcription factors.
Reference: Núria Radó-Trilla , Krisztina Arató , Cinta Pegueroles , Alicia Raya , Susana de la Luna, M.Mar Albà. Key role of amino acid repeat expansions in the functional diversification of duplicated transcription factors. bioRxiv http://dx.doi.org/10.1101/014910.@biorxivpreprint
Update: published in MBE here.