Darwinian selection for sites of Asn-linked glycosylation in phylogenetically disparate eukaryotes and viruses Export

@article{citeulike:5428242, abstract = {10.1073/pnas.0905818106 Numerous protists and rare fungi have truncated Asn-linked glycan precursors and lack N-glycan-dependent quality control (QC) systems for glycoprotein folding in the endoplasmic reticulum. Here, we show that the abundance of sequons (NXT or NXS), which are sites for N-glycosylation of secreted and membrane proteins, varies by more than a factor of 4 among phylogenetically diverse eukaryotes, based on a few variables. There is positive correlation between the density of sequons and the AT content of coding regions, although no causality can be inferred. In contrast, there appears to be Darwinian selection for sequons containing Thr, but not Ser, in eukaryotes that have N-glycan-dependent QC systems. Selection for sequons with Thr, which nearly doubles the sequon density in human secreted and membrane proteins, occurs by an increased conditional probability that Asn and Thr are present in sequons rather than elsewhere. Increasing sequon densities of the hemagglutinin (HA) of influenza viruses A/H3N2 and A/H1N1 during the past few decades of human infection also result from an increased conditional probability that Asn, Thr, and Ser are present in sequons rather than elsewhere. In contrast, there is no selection on sequons by this mechanism in HA of A/H5N1 or 2009 A/H1N1 (Swine flu). Very strong selection for sequons with both Thr and Ser in glycoprotein of 120,000 (gp120) of HIV and related retroviruses results from this same mechanism, as well as amino acid composition bias and increases in AT content. We conclude that there is Darwinian selection for sequons in phylogenetically disparate eukaryotes and viruses.}, author = {Cui, Jike and Smith, Temple and Robbins, Phillips W. and Samuelson, John}, citeulike-article-id = {5428242}, citeulike-linkout-0 = {http://dx.doi.org/10.1073/pnas.0905818106}, citeulike-linkout-1 = {http://www.pnas.org/content/106/32/13421.abstract}, citeulike-linkout-2 = {http://www.pnas.org/content/106/32/13421.full.pdf}, day = {11}, doi = {10.1073/pnas.0905818106}, journal = {Proceedings of the National Academy of Sciences}, keywords = {eukaryota, evolution, virus}, month = {August}, number = {32}, pages = {13421--13426}, posted-at = {2009-08-13 04:23:41}, priority = {2}, title = {Darwinian selection for sites of Asn-linked glycosylation in phylogenetically disparate eukaryotes and viruses}, url = {http://dx.doi.org/10.1073/pnas.0905818106}, volume = {106}, year = {2009} }

TY - JOUR ID - citeulike:5428242 L3 - citeulike-article-id:5428242 N2 - 10.1073/pnas.0905818106 Numerous protists and rare fungi have truncated Asn-linked glycan precursors and lack N-glycan-dependent quality control (QC) systems for glycoprotein folding in the endoplasmic reticulum. Here, we show that the abundance of sequons (NXT or NXS), which are sites for N-glycosylation of secreted and membrane proteins, varies by more than a factor of 4 among phylogenetically diverse eukaryotes, based on a few variables. There is positive correlation between the density of sequons and the AT content of coding regions, although no causality can be inferred. In contrast, there appears to be Darwinian selection for sequons containing Thr, but not Ser, in eukaryotes that have N-glycan-dependent QC systems. Selection for sequons with Thr, which nearly doubles the sequon density in human secreted and membrane proteins, occurs by an increased conditional probability that Asn and Thr are present in sequons rather than elsewhere. Increasing sequon densities of the hemagglutinin (HA) of influenza viruses A/H3N2 and A/H1N1 during the past few decades of human infection also result from an increased conditional probability that Asn, Thr, and Ser are present in sequons rather than elsewhere. In contrast, there is no selection on sequons by this mechanism in HA of A/H5N1 or 2009 A/H1N1 (Swine flu). Very strong selection for sequons with both Thr and Ser in glycoprotein of 120,000 (gp120) of HIV and related retroviruses results from this same mechanism, as well as amino acid composition bias and increases in AT content. We conclude that there is Darwinian selection for sequons in phylogenetically disparate eukaryotes and viruses. IS - 32 JF - Proceedings of the National Academy of Sciences EP - 13426 TI - Darwinian selection for sites of Asn-linked glycosylation in phylogenetically disparate eukaryotes and viruses VL - 106 SP - 13421 KW - eukaryota KW - evolution KW - virus AU - Cui, Jike AU - Smith, Temple AU - Robbins, Phillips AU - Samuelson, John PY - 2009/08/11/ UR - http://dx.doi.org/10.1073/pnas.0905818106 ER -