title: A comprehensive functional analysis of ancestral human signal peptides.
abstract: With the sequencing of the Neandertal genome, it has become possible to identify amino acid substitutions that occurred on the human lineage since its separation from the Neandertal lineage. Conceptually, it will therefore be possible to functionally analyze all such amino acid substitutions in the future. Here, we analyze the function of substitutions that occurred during recent human evolution in N-terminal signal peptides. We develop a high-throughput flow cytometry-based assay to analyze signal peptide efficiency as the ratio of surface to total reporter protein per live cell. Such ratios differed significantly among signal peptides derived from different human genes. However, no modern human signal peptide differed significantly from its ancestral counterpart, an observation compatible with the predictions of the neutral theory of molecular evolution.
authors.forename: Matthias
authors.initials: M
authors.lastname: Gralle
authors.forename: Svante
authors.initials: S
authors.lastname: Pääbo
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D019143:Evolution, Molecular; D005580:Fossils; D015894:Genome, Human; D006801:Humans; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D021382:Protein Sorting Signals