Amino Acid Animals Computational Biology de novo gene DNA Evolution Genetic Genome human Humans lncRNA Mice Molecular Molecular Sequence Data Nucleic Acid Proteins Proteins: chemistry Proteins: genetics Repetitive Sequences ribosome profiling RNA-Seq Selection Sequence Analysis transcriptomics yeast
2010 |
Mularoni, Loris, Ledda, Alice, Toll-Riera, Macarena, Albà, M Mar Natural selection drives the accumulation of amino acid tandem repeats in human proteins. (Article) Genome research, 20 (6), pp. 745–54, 2010, ISSN: 1549-5469. (Abstract | Links | BibTeX | Tags: Amino Acid, Amino Acid Sequence, Amino Acids, Amino Acids: chemistry, Amino Acids: genetics, Animals, Genetic, Humans, Molecular Sequence Data, Proteins, Proteins: chemistry, Proteins: genetics, Repetitive Sequences, Selection, Sequence Homology) @article{Mularoni2010, title = {Natural selection drives the accumulation of amino acid tandem repeats in human proteins.}, author = {Mularoni, Loris and Ledda, Alice and Toll-Riera, Macarena and Albà, M Mar}, url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2877571&tool=pmcentrez&rendertype=abstract}, issn = {1549-5469}, year = {2010}, date = {2010-01-01}, journal = {Genome research}, volume = {20}, number = {6}, pages = {745--54}, abstract = {Amino acid tandem repeats are found in a large number of eukaryotic proteins. They are often encoded by trinucleotide repeats and exhibit high intra- and interspecies size variability due to the high mutation rate associated with replication slippage. The extent to which natural selection is important in shaping amino acid repeat evolution is a matter of debate. On one hand, their high frequency may simply reflect their high probability of expansion by slippage, and they could essentially evolve in a neutral manner. On the other hand, there is experimental evidence that changes in repeat size can influence protein-protein interactions, transcriptional activity, or protein subcellular localization, indicating that repeats could be functionally relevant and thus shaped by selection. To gauge the relative contribution of neutral and selective forces in amino acid repeat evolution, we have performed a comparative analysis of amino acid repeat conservation in a large set of orthologous proteins from 12 vertebrate species. As a neutral model of repeat evolution we have used sequences with the same DNA triplet composition as the coding sequences--and thus expected to be subject to the same mutational forces--but located in syntenic noncoding genomic regions. The results strongly indicate that selection has played a more important role than previously suspected in amino acid tandem repeat evolution, by increasing the repeat retention rate and by modulating repeat size. The data obtained in this study have allowed us to identify a set of 92 repeats that are postulated to play important functional roles due to their strong selective signature, including five cases with direct experimental evidence.}, keywords = {Amino Acid, Amino Acid Sequence, Amino Acids, Amino Acids: chemistry, Amino Acids: genetics, Animals, Genetic, Humans, Molecular Sequence Data, Proteins, Proteins: chemistry, Proteins: genetics, Repetitive Sequences, Selection, Sequence Homology} } Amino acid tandem repeats are found in a large number of eukaryotic proteins. They are often encoded by trinucleotide repeats and exhibit high intra- and interspecies size variability due to the high mutation rate associated with replication slippage. The extent to which natural selection is important in shaping amino acid repeat evolution is a matter of debate. On one hand, their high frequency may simply reflect their high probability of expansion by slippage, and they could essentially evolve in a neutral manner. On the other hand, there is experimental evidence that changes in repeat size can influence protein-protein interactions, transcriptional activity, or protein subcellular localization, indicating that repeats could be functionally relevant and thus shaped by selection. To gauge the relative contribution of neutral and selective forces in amino acid repeat evolution, we have performed a comparative analysis of amino acid repeat conservation in a large set of orthologous proteins from 12 vertebrate species. As a neutral model of repeat evolution we have used sequences with the same DNA triplet composition as the coding sequences--and thus expected to be subject to the same mutational forces--but located in syntenic noncoding genomic regions. The results strongly indicate that selection has played a more important role than previously suspected in amino acid tandem repeat evolution, by increasing the repeat retention rate and by modulating repeat size. The data obtained in this study have allowed us to identify a set of 92 repeats that are postulated to play important functional roles due to their strong selective signature, including five cases with direct experimental evidence. |
2009 |
Salichs, Eulàlia, Ledda, Alice, Mularoni, Loris, Albà, M Mar, de la Luna, Susana PLoS genetics, 5 (3), pp. e1000397, 2009, ISSN: 1553-7404. (Abstract | Links | BibTeX | Tags: Amino Acids, Cell Line, Cell Nucleus, Cell Nucleus: chemistry, Cell Nucleus: genetics, Cell Nucleus: metabolism, Genome, Histidine, Histidine: chemistry, Histidine: genetics, Histidine: metabolism, human, Humans, Molecular Sequence Data, Nuclear Localization Signals, Nuclear Proteins, Nuclear Proteins: chemistry, Nuclear Proteins: genetics, Nuclear Proteins: metabolism, Protein Transport, Proteins, Proteins: chemistry, Proteins: genetics, Proteins: metabolism, Sequence Alignment, Tandem Repeat Sequences) @article{Salichs2009, title = {Genome-wide analysis of histidine repeats reveals their role in the localization of human proteins to the nuclear speckles compartment.}, author = {Salichs, Eulàlia and Ledda, Alice and Mularoni, Loris and Albà, M Mar and de la Luna, Susana}, url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2644819&tool=pmcentrez&rendertype=abstract}, issn = {1553-7404}, year = {2009}, date = {2009-01-01}, journal = {PLoS genetics}, volume = {5}, number = {3}, pages = {e1000397}, abstract = {Single amino acid repeats are prevalent in eukaryote organisms, although the role of many such sequences is still poorly understood. We have performed a comprehensive analysis of the proteins containing homopolymeric histidine tracts in the human genome and identified 86 human proteins that contain stretches of five or more histidines. Most of them are endowed with DNA- and RNA-related functions, and, in addition, there is an overrepresentation of proteins expressed in the brain and/or nervous system development. An analysis of their subcellular localization shows that 15 of the 22 nuclear proteins identified accumulate in the nuclear subcompartment known as nuclear speckles. This localization is lost when the histidine repeat is deleted, and significantly, closely related paralogous proteins without histidine repeats also fail to localize to nuclear speckles. Hence, the histidine tract appears to be directly involved in targeting proteins to this compartment. The removal of DNA-binding domains or treatment with RNA polymerase II inhibitors induces the re-localization of several polyhistidine-containing proteins from the nucleoplasm to nuclear speckles. These findings highlight the dynamic relationship between sites of transcription and nuclear speckles. Therefore, we define the histidine repeats as a novel targeting signal for nuclear speckles, and we suggest that these repeats are a way of generating evolutionary diversification in gene duplicates. These data contribute to our better understanding of the physiological role of single amino acid repeats in proteins.}, keywords = {Amino Acids, Cell Line, Cell Nucleus, Cell Nucleus: chemistry, Cell Nucleus: genetics, Cell Nucleus: metabolism, Genome, Histidine, Histidine: chemistry, Histidine: genetics, Histidine: metabolism, human, Humans, Molecular Sequence Data, Nuclear Localization Signals, Nuclear Proteins, Nuclear Proteins: chemistry, Nuclear Proteins: genetics, Nuclear Proteins: metabolism, Protein Transport, Proteins, Proteins: chemistry, Proteins: genetics, Proteins: metabolism, Sequence Alignment, Tandem Repeat Sequences} } Single amino acid repeats are prevalent in eukaryote organisms, although the role of many such sequences is still poorly understood. We have performed a comprehensive analysis of the proteins containing homopolymeric histidine tracts in the human genome and identified 86 human proteins that contain stretches of five or more histidines. Most of them are endowed with DNA- and RNA-related functions, and, in addition, there is an overrepresentation of proteins expressed in the brain and/or nervous system development. An analysis of their subcellular localization shows that 15 of the 22 nuclear proteins identified accumulate in the nuclear subcompartment known as nuclear speckles. This localization is lost when the histidine repeat is deleted, and significantly, closely related paralogous proteins without histidine repeats also fail to localize to nuclear speckles. Hence, the histidine tract appears to be directly involved in targeting proteins to this compartment. The removal of DNA-binding domains or treatment with RNA polymerase II inhibitors induces the re-localization of several polyhistidine-containing proteins from the nucleoplasm to nuclear speckles. These findings highlight the dynamic relationship between sites of transcription and nuclear speckles. Therefore, we define the histidine repeats as a novel targeting signal for nuclear speckles, and we suggest that these repeats are a way of generating evolutionary diversification in gene duplicates. These data contribute to our better understanding of the physiological role of single amino acid repeats in proteins. |
