Comparative aspects of polyglutamine binding domain in PQBP-1 among Vertebrata

► Different Vertebrata lineages show different domain compositions of PQBP-1. ► None of PQBP-1 or three polyQ proteins appears to be able to interact in Amphibia. ► Eutherian PQBP-1 retains the full form of polyQ-binding domain. ► Mammalian BRN-2s are ready for the interaction with PQBP-1. ► Huntingtin or ATAXIN-1 retains a long polyQ in specific eutherian lineages.