Expansions of amino acid tracts in proteins are famous for causing a number of neurodegenerative and developmental diseases. However, these regions are also an important motor for evolution, as recently shown in an article appeared in Molecular Biology and Evolution coauthored by the Evolutionary Genomics group of GRIB (IMIM-UPF) led by Mar Albà and the Gene Function group of CRG led by Susana de la Luna.
The complexity of vertebrates is related to two whole genome duplications occurred at the origin of the group. After these events, many developmental regulators were retained in multiple copies and later acquired different functions. The authors have shown that a large number of transcription factors gained new amino acid tandem repeats after the duplication. In experiments performed in families containing poly-alanine tracts, deletion of the repeat recapitulates the ancestral protein transcriptional activity, making the two copies alike again. The results support the idea that repeats played an important role in in the diversification of transcriptional networks during vertebrate evolution.
Article ref.: Núria Radó-Trilla, Krisztina Arató, Cinta Pegueroles, Alicia Raya, Susana de la Luna* and M.Mar Albà*. Key role of amino acid repeat expansions in the functional diversification of duplicated transcription factors. Molecular Biology and Evolution, April 29, 2015, Advance Access. *co-corresponding