Phosphotyrosine is the phosphorylated version of the amino acid tyrosine, which results from the activation of intracellular protein kinases (e.g. via growth factors) during normal growth and development, well as in transformation and oncogenesis. Phosphorylation of histidine, serine, threonine and tyrosine residues acts as a signaling system to control many cellular signaling pathways. The cellular networks which rely on these signals can be very complex, so phosphorylation often occurs on multiple sites on a given protein. This phosphorylation is reversible, allowing for exquisite regulation and modulation. Phosphotyrosine is one of the most frequent post-translational modifications that regulate protein-protein interaction and enzyme activity in eukaryotic cells.
-Western%20Blot-NB600-907-img0001.jpg "Western Blot: Phosphotyrosine Antibody")
The most abundant population of target proteins for tyrosine phosphorylation is cell surface glycoproteins. Panels of phosphotyrosine antibodies were initially used to profile transformed and growth-factor treated cells (1) as well as characterize cellular tyrosine phosphorylation (2). Certain phosphotyrosine antibodies effectively block downstream functional activity of various signaling pathways (3,4). Peptide microarray studies on phosphotyrosine antibodies were used to characterize their substrate specificity (5). More recently, a variety of different phosphoproteomic SILAC-based (stable isotope labeling with amino acids in cell culture) strategies for studying tyrosine kinase signaling were compared, and found to be complementary (6). Mithoe, et. al. have shown another targeted quantitative phosphoproteomics approach with phosphotyrosine antibodies to be effective in detecting new phosphorylation targets and peptides (7).
Novus Biologicals offers Phosphotyrosine reagents for your research needs including:
