Evolutionary fates of universal stress protein paralogs in Platyhelminthes

BMC Evolutionary Biology

Martin Pablo Cancela¹  Laus Brisolara Corra²  Sergio Martin Espinola³ 

[1] Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil;Programa de Ps Graduao em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil;Programa de Ps Graduao em Gentica e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil

关键词: Stress responsive proteins;    Flatworms;    Evolutionary patterns;    Pseudogenes;    Functional divergence;   

DOI  :  10.1186/s12862-018-1129-x

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

Universal stress proteins (USPs) are present in all domains of life. Their expression is upregulated in response to a large variety of stress conditions. The functional diversity found in this protein family, paired with the sequence degeneration of the characteristic ATP-binding motif, suggests a complex evolutionary pattern for the paralogous USP-encoding genes. In this work, we investigated the origin, genomic organization, expression patterns and evolutionary history of the USP gene family in species of the phylum Platyhelminthes. Our data showed a cluster organization, a lineage-specific distribution, and the presence of several pseudogenes among the USP gene copies identified. The absence of a well conserved -CCAATCA- motif in the promoter region was positively correlated with low or null levels of gene expression, and with amino acid changes within the ligand binding motifs. Despite evidence of the pseudogenization of various USP genes, we detected an important functional divergence at several residues, mostly located near sites that are critical for ligand interaction. Our results provide a broad framework for the evolution of the USP gene family, based on the emergence of new paralogs that face very contrasting fates, including pseudogenization, subfunctionalization or neofunctionalization. This framework aims to explain the sequence and functional diversity of this gene family, providing a foundation for future studies in other taxa in which USPs occur.

【 授权许可】

CC BY