A alysis of variatio site i post-tra slatio al modificatio

Post-translational modification (PTM) is a modification of a protein after its translation. This modification can occur either by the covalent addition of particular chemical groups or by enzymatic cleavage of peptide bond. Post-translational modifications play an important role in signaling pathways, protein stability, oxidative regulation of proteins and cellular localization. Variations of the modification sites can highly affect or disrupt these important biological processes and can lead to disease. The aim of this study was to analyze the variation sites of post-translational modification sites and their relation to disease. Experimentally verified post-translational modifications were downloaded from Human Protein Reference Database (HPRD) web site. The Single-nucleotide Polymorphism (SNP) data, which contains both pathogenic and neutral missense variations, were matched against the posttranslational data to filter out Post-translational Modifications (PTMs) in variation sites. DRUMs, WAVe and Locus specific databases were used to separate disease-causing variations, which occur at the PTM sites. To study the conservation of the variation sites ConSurf was used and a statistical analysis was done by using hyper geometric distribution and ttest. Disease causing variations were found in both pathogenic and neutral datasets. The conservation score of disease causing variation has indicated that they are more conserved than the benign variations. To further study the variation sites of PTM one can investigate the gene function of PTMs in order to understand which molecular and cellular functions are disrupted by disease causing variations.