This web page was produced as an assignment for Genetics 564, an undergraduate capstone course at UW-Madison.
What are post-translational modifications?
Post-translational modifications (PTMs) increase the functional diversity of the proteome by the addition of functional groups or proteins, proteolytic cleavage, or degradation of entire proteins. Several types of PTMs exist including phosphorylation, glycosylation, ubiquitination, nitrosylation, methylation, acetylation, lipidation and proteolysis. Because of this, understanding PTMs is critical to understanding the proteome. [1] The figure to the right describes the different types of PTMs
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Post-translational Modifications of StAR
Tools such as NetPhos use algorithms to infer potential phosphorylation sites based on an input protein sequence. I used NetPhos to uncover putative phosphorylation sites in the StAR protein of each of my homologs; the results are depicted below. Lines that reach above the pink threshold have a high level of confidence for being true phosphorylation sites. Since StAR is highly conserved across all of the depicted homologs except C. elegans, it is not very surprising that the predicted phosphorylation sites are extremely similar.
Human
Homo sapiens |
Rhesus macaque
Macaca mulatta |
Brown rat
Rattus norvegicus |
House mouse
Mus musculus |
Conclusion
Understanding PTMs is critical to fully understanding the proteome. Tools such as NetPhos can predict putative phosphorylation sites based on a given protein sequence. All of the depicted homologs for StAR, except C. elegans, show very similar predicted phosphorylation sites which makes sense since StAR is highly conserved across all of them.
References
[1] Overview of Post-Translational Modifications (PTMs). (n.d.). Retrieved Apr. 11, 2019 from https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-biology-learning-center/protein-biology-resource-library/pierce-protein-methods/overview-post-translational-modification.html
[1] Overview of Post-Translational Modifications (PTMs). (n.d.). Retrieved Apr. 11, 2019 from https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-biology-learning-center/protein-biology-resource-library/pierce-protein-methods/overview-post-translational-modification.html
Header image: https://hipwallpaper.com/protein-backgrounds/