Tunicates Illuminate the Enigmatic Evolution of Chordate Metallothioneins by Gene Gains and Losses, Independent Modular Expansions, and Functional Convergences

To investigate novel patterns and processes of protein evolution, we have focused in the metallothioneins (MTs), a singular group of metal-binding, cysteine-rich proteins that, due to their high degree of sequence diversity, still represents a 'black hole' in Evolutionary Biology....

Descripción completa

Detalles Bibliográficos
Autores: Calatayud, Sara, Garcia-Risco, Mario, Palacios Bonilla, Òscar, Capdevila Vidal, Mercè, Cañestro García, Cristian, Albalat Rodríguez, Ricard
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/183503
Acceso en línea:https://hdl.handle.net/2445/183503
Access Level:acceso abierto
Palabra clave:Cordats
Urocordats
Chordata
Tunicata
Descripción
Sumario:To investigate novel patterns and processes of protein evolution, we have focused in the metallothioneins (MTs), a singular group of metal-binding, cysteine-rich proteins that, due to their high degree of sequence diversity, still represents a 'black hole' in Evolutionary Biology. We have identified and analyzed more than 160 new MTs in nonvertebrate chordates (especially in 37 species of ascidians, 4 thaliaceans, and 3 appendicularians) showing that prototypic tunicate MTs are mono-modular proteins with a pervasive preference for cadmium ions, whereas vertebrate and cephalochordate MTs are bimodular proteins with diverse metal preferences. These structural and functional differences imply a complex evolutionary history of chordate MTs-including de novo emergence of genes and domains, processes of convergent evolution, events of gene gains and losses, and recurrent amplifications of functional domains-that would stand for an unprecedented case in the field of protein evolution.