Amino Acid Animals Computational Biology Databases de novo gene DNA Evolution Genetic Genome human Humans Mice Molecular Molecular Sequence Data Proteins Proteins: chemistry Proteins: genetics Repetitive Sequences ribosome profiling RNA-Seq Selection Sequence Analysis Sequence Homology transcriptomics yeast
2007 |
Mularoni, Loris, Veitia, Reiner A, Albà, M Mar Highly constrained proteins contain an unexpectedly large number of amino acid tandem repeats. (Article) Genomics, 89 (3), pp. 316–25, 2007, ISSN: 0888-7543. (Abstract | Links | BibTeX | Tags: Amino Acid, Amino Acid Sequence, Animals, Complementary, Conserved Sequence, DNA, Evolution, Genetic, Humans, Mice, Molecular, Point Mutation, Proteins, Proteins: chemistry, Proteins: genetics, Repetitive Sequences, Selection, Trinucleotide Repeats) @article{Mularoni2007, title = {Highly constrained proteins contain an unexpectedly large number of amino acid tandem repeats.}, author = {Mularoni, Loris and Veitia, Reiner A and Albà, M Mar}, url = {http://www.ncbi.nlm.nih.gov/pubmed/17196365}, issn = {0888-7543}, year = {2007}, date = {2007-01-01}, journal = {Genomics}, volume = {89}, number = {3}, pages = {316--25}, abstract = {Single-amino-acid tandem repeats are very common in mammalian proteins but their function and evolution are still poorly understood. Here we investigate how the variability and prevalence of amino acid repeats are related to the evolutionary constraints operating on the proteins. We find a significant positive correlation between repeat size difference and protein nonsynonymous substitution rate in human and mouse orthologous genes. This association is observed for all the common amino acid repeat types and indicates that rapid diversification of repeat structures, involving both trinucleotide slippage and nucleotide substitutions, preferentially occurs in proteins subject to low selective constraints. However, strikingly, we also observe a significant negative correlation between the number of repeats in a protein and the gene nonsynonymous substitution rate, particularly for glutamine, glycine, and alanine repeats. This implies that proteins subject to strong selective constraints tend to contain an unexpectedly high number of repeats, which tend to be well conserved between the two species. This is consistent with a role for selection in the maintenance of a significant number of repeats. Analysis of the codon structure of the sequences encoding the repeats shows that codon purity is associated with high repeat size interspecific variability. Interestingly, polyalanine and polyglutamine repeats associated with disease show very distinctive features regarding the degree of repeat conservation and the protein sequence selective constraints.}, keywords = {Amino Acid, Amino Acid Sequence, Animals, Complementary, Conserved Sequence, DNA, Evolution, Genetic, Humans, Mice, Molecular, Point Mutation, Proteins, Proteins: chemistry, Proteins: genetics, Repetitive Sequences, Selection, Trinucleotide Repeats} } Single-amino-acid tandem repeats are very common in mammalian proteins but their function and evolution are still poorly understood. Here we investigate how the variability and prevalence of amino acid repeats are related to the evolutionary constraints operating on the proteins. We find a significant positive correlation between repeat size difference and protein nonsynonymous substitution rate in human and mouse orthologous genes. This association is observed for all the common amino acid repeat types and indicates that rapid diversification of repeat structures, involving both trinucleotide slippage and nucleotide substitutions, preferentially occurs in proteins subject to low selective constraints. However, strikingly, we also observe a significant negative correlation between the number of repeats in a protein and the gene nonsynonymous substitution rate, particularly for glutamine, glycine, and alanine repeats. This implies that proteins subject to strong selective constraints tend to contain an unexpectedly high number of repeats, which tend to be well conserved between the two species. This is consistent with a role for selection in the maintenance of a significant number of repeats. Analysis of the codon structure of the sequences encoding the repeats shows that codon purity is associated with high repeat size interspecific variability. Interestingly, polyalanine and polyglutamine repeats associated with disease show very distinctive features regarding the degree of repeat conservation and the protein sequence selective constraints. |
2004 |
Albà, M Mar, Guigó, Roderic Comparative analysis of amino acid repeats in rodents and humans. (Article) Genome research, 14 (4), pp. 549–54, 2004, ISSN: 1088-9051. (Abstract | Links | BibTeX | Tags: Amino Acid, Amino Acid: genetics, Amino Acid: physiology, Animals, Chromosome Mapping, Chromosome Mapping: methods, Chromosome Mapping: statistics & numerical data, Computational Biology, Computational Biology: methods, Computational Biology: statistics & numerical data, GC Rich Sequence, GC Rich Sequence: genetics, Humans, Mice, Proteins, Proteins: chemistry, Proteins: genetics, Proteins: physiology, Rats, Repetitive Sequences, Trinucleotide Repeats, Trinucleotide Repeats: genetics) @article{Alba2004, title = {Comparative analysis of amino acid repeats in rodents and humans.}, author = {Albà, M Mar and Guigó, Roderic}, url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=383298&tool=pmcentrez&rendertype=abstract}, issn = {1088-9051}, year = {2004}, date = {2004-01-01}, journal = {Genome research}, volume = {14}, number = {4}, pages = {549--54}, abstract = {Amino acid tandem repeats, also called homopolymeric tracts, are extremely abundant in eukaryotic proteins. To gain insight into the genome-wide evolution of these regions in mammals, we analyzed the repeat content in a large data set of rat-mouse-human orthologs. Our results show that human proteins contain more amino acid repeats than rodent proteins and that trinucleotide repeats are also more abundant in human coding sequences. Using the human species as an outgroup, we were able to address differences in repeat loss and repeat gain in the rat and mouse lineages. In this data set, mouse proteins contain substantially more repeats than rat proteins, which can be at least partly attributed to a higher repeat loss in the rat lineage. The data are consistent with a role for trinucleotide slippage in the generation of novel amino acid repeats. We confirm the previously observed functional bias of proteins with repeats, with overrepresentation of transcription factors and DNA-binding proteins. We show that genes encoding amino acid repeats tend to have an unusually high GC content, and that differences in coding GC content among orthologs are directly related to the presence/absence of repeats. We propose that the different GC content isochore structure in rodents and humans may result in an increased amino acid repeat prevalence in the human lineage.}, keywords = {Amino Acid, Amino Acid: genetics, Amino Acid: physiology, Animals, Chromosome Mapping, Chromosome Mapping: methods, Chromosome Mapping: statistics & numerical data, Computational Biology, Computational Biology: methods, Computational Biology: statistics & numerical data, GC Rich Sequence, GC Rich Sequence: genetics, Humans, Mice, Proteins, Proteins: chemistry, Proteins: genetics, Proteins: physiology, Rats, Repetitive Sequences, Trinucleotide Repeats, Trinucleotide Repeats: genetics} } Amino acid tandem repeats, also called homopolymeric tracts, are extremely abundant in eukaryotic proteins. To gain insight into the genome-wide evolution of these regions in mammals, we analyzed the repeat content in a large data set of rat-mouse-human orthologs. Our results show that human proteins contain more amino acid repeats than rodent proteins and that trinucleotide repeats are also more abundant in human coding sequences. Using the human species as an outgroup, we were able to address differences in repeat loss and repeat gain in the rat and mouse lineages. In this data set, mouse proteins contain substantially more repeats than rat proteins, which can be at least partly attributed to a higher repeat loss in the rat lineage. The data are consistent with a role for trinucleotide slippage in the generation of novel amino acid repeats. We confirm the previously observed functional bias of proteins with repeats, with overrepresentation of transcription factors and DNA-binding proteins. We show that genes encoding amino acid repeats tend to have an unusually high GC content, and that differences in coding GC content among orthologs are directly related to the presence/absence of repeats. We propose that the different GC content isochore structure in rodents and humans may result in an increased amino acid repeat prevalence in the human lineage. |
