Evolutionary History of Arabidopsis thaliana Aminoacyl-tRNA Synthetase Dual-Targeted Proteins

Autor(es)

Brandao, Marcelo M. ^[1] ; Silva-Filho, Marcio C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Genet, Escola Super Agr Luiz de Queiroz, Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular Biology and Evolution; v. 28, n. 1, p. 79-85, JAN 2011.
• Citações Web of Science: 11

Resumo

Aminoacyl-transfer RNA (tRNA) synthetases (aaRS) are key players in translation and act early in protein synthesis by mediating the attachment of amino acids to their cognate tRNA molecules. In plants, protein synthesis may occur in three subcellular compartments (cytosol, mitochondria, and chloroplasts), which requires multiple versions of the protein to be correctly delivered to its proper destination. The organellar aaRS are nuclear encoded and equipped with targeting information at the N-terminal sequence, which enables them to be specifically translocated to their final location. Most of the aaRS families present organellar proteins that are dual targeted to mitochondria and chloroplasts. Here, we examine the dual targeting behavior of aaRS from an evolutionary perspective. Our results show that Arabidopsis thaliana aaRS sequences are a result of a horizontal gene transfer event from bacteria. However, there is no evident bias indicating one single ancestor (Cyanobacteria or Proteobacteria). The dual-targeted aaRS phylogenetic relationship was characterized into two different categories (paralogs and homologs) depending on the state recovered for both dual-targeted and cytosolic proteins. Taken together, our results suggest that the dual-targeted condition is a gain-of-function derived from gene duplication. Selection may have maintained the original function in at least one of the copies as the additional copies diverged. (AU)

• Processo FAPESP: 05/54618-9 - Decifrando os mecanismos moleculares envolvidos na localização intracelular de proteínas em plantas
• Beneficiário: Márcio de Castro Silva Filho
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/52067-3 - Herbivoria e o transporte intracelular de proteínas
• Beneficiário: Márcio de Castro Silva Filho
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático