title: In silico determination of intracellular glycosylation and phosphorylation sites in human selectins: implications for biological function.
abstract: Post-translational modifications provide the proteins with the possibility to perform functions in addition to those determined by their primary sequence. However, analysis of multifunctional protein structures in the environment of cells and body fluids is made especially difficult by the presence of other interacting proteins. Bioinformatics tools are therefore helpful to predict protein multifunctionality through the identification of serine and threonine residues wherein the hydroxyl group is likely to become modified by phosphorylation or glycosylation. Moreover, serines and threonines where both modifications are likely to occur can also be predicted (YinYang sites), to suggest further functional versatility. Structural modifications of hydroxyl groups of P-, E-, and L-selectins have been predicted and possible functions resulting from such modifications are proposed. Functional changes of the three selectins are based on the assumption that transitory and reversible protein modifications by phosphate and O-GlcNAc cause specific conformational changes and generate binding sites for other proteins. The computer-assisted prediction of glycosylation and phosphorylation sites in selectins should be helpful to assess the contribution of dynamic protein modifications in selectin-mediated inflammatory responses and cell-cell adhesion processes that are difficult to determine experimentally.
authors.affiliation: Institute of Molecular Sciences and Bioinformatics, Lahore, Pakistan.
authors.forename: Ishtiaq
authors.initials: I
authors.lastname: Ahmad
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Hoessli
authors.forename: Ramneek
authors.initials: R
authors.lastname: Gupta
authors.forename: Evelyne
authors.initials: E
authors.lastname: Walker-Nasir
authors.forename: Saleem M
authors.initials: SM
authors.lastname: Rafik
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
authors.forename: Abdul Rauf
authors.initials: AR
authors.lastname: Shakoori
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D019295:Computational Biology / Q000379:methods*; D030562:Databases, Protein; D019040:E-Selectin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D019041:L-Selectin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019007:P-Selectin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary; D019087:Selectins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D019040:E-Selectin; D019007:P-Selectin; D019087:Selectins; D019041:L-Selectin