Role of alternative phosphorylation and O-glycosylation of erythropoietinreceptor in modulating its function: an in silico study

Authors : Humera KAUSAR, Sana GUL, Waqar AHMAD, Sana AWAN, Muhammad Tahir SARWAR, Bushra IJAZ, Muhammad ANSAR, Sultan ASAD, Sajida HASSAN

Pages : 816-825

View : 13 | Download : 9

Publication Date : 2017-12-01

Article Type : Research Paper

Abstract :Detailed knowledge of the three-dimensional insert ignore into journalissuearticles values(3D); structure of a protein is essential for the proper understanding of its functioninsert ignore into journalissuearticles values(s); that could be modified through posttranslational modifications insert ignore into journalissuearticles values(PTMs);. Among these PTMs, alterations of serine/threonine residues of a protein through phosphorylation and O-glycosylation are extremely dynamic and could modulate the functions of a protein by affecting their 3D structure. Potential of a protein for certain PTMs could be evaluated through computer-based methods. Erythropoietin insert ignore into journalissuearticles values(EPO); is a multifunctional protein that primarily regulates red blood cell production and is also involved in other nonhematopoietic functions; for example, EPO also has cardioprotective and neuroprotective effects. In this study, multifunctional EPO behavior has been revealed based on transient modifications of its receptor. In this study, PTMs of erythropoietin receptor insert ignore into journalissuearticles values(EPO-R); were predicted using neural network tools, and the possible effects of these modifications are suggested. Phosphorylation and O-glycosylation at serine 380 and 444 of the cytoplasmic domain of EPO-R seem to have an antagonistic role in controlling signaling events induced by EPO. O-glycosylation at threonine 423 might hinder ß-TrCP insert ignore into journalissuearticles values(a ubiquitin ligase); binding, which ubiquitinates at K 428, and ultimately results in the recycling of EPO-R, thus increasing EPO sensitivity. In contrast, the phosphorylated form of the same residue inhibits the recycling of EPO-R and thereby decreases the EPO sensitivity. Additionally, the interplay of O-glycosylation modification at serine 478 and phosphorylation at tyrosine 479 might help in controlling the duration of EPO-induced signaling.
Keywords : EPO receptor, phosphorylation, O glycosylation, three dimensional 3D, structure, multifunctional behavior and EPO