title: Evolutionary Ancestry of Eukaryotic Protein Kinases and Choline Kinases.
abstract: The reversible phosphorylation of proteins catalyzed by protein kinases in eukaryotes supports an important role for eukaryotic protein kinases (ePKs) in the emergence of nucleated cells in the third superkingdom of life. Choline kinases (ChKs) could also be critical in the early evolution of eukaryotes, because of their function in the biosynthesis of phosphatidylcholine, which is unique to eukaryotic membranes. However, the genomic origins of ePKs and ChKs are unclear. The high degeneracy of protein sequences and broad expansion of ePK families have made this fundamental question difficult to answer. In this study, we identified two class-I aminoacyl-tRNA synthetases with high similarities to consensus amino acid sequences of human protein-serine/threonine kinases. Comparisons of primary and tertiary structures supported that ePKs and ChKs evolved from a common ancestor related to glutaminyl aminoacyl-tRNA synthetases, which may have been one of the key factors in the successful of emergence of ancient eukaryotic cells from bacterial colonies.
authors.affiliation: From the Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, British Columbia V6T 2B5.
authors.forename: Shenshen
authors.initials: S
authors.lastname: Lai
authors.affiliation: the Department of Computer Science, University of British Columbia, Vancouver, British Columbia V6T 1Z4, and.
authors.forename: Javad
authors.initials: J
authors.lastname: Safaei
authors.affiliation: From the Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, British Columbia V6T 2B5, the Kinexus Bioinformatics Corporation, Vancouver, British Columbia V6P 6T3, Canada spelech@kinexus.ca.
authors.forename: Steven
authors.identifier: http://orcid.org/0000-0003-1112-903X
authors.initials: S
authors.lastname: Pelech
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics*; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D002797:Choline Kinase / Q000737:chemistry / Q000235:genetics*; D016384:Consensus Sequence; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics*; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D011494:Protein Kinases; D002797:Choline Kinase; D000604:Amino Acyl-tRNA Synthetases
keywords: aminoacyl tRNA synthetase; choline kinase; glutaminyl aminoacyl tRNA synthetase; phosphatidylcholine biosynthesis; protein evolution; protein kinase; protein phosphorylation; signal transduction