EPQpYEEIPIYL(Cat No.:I044200)is a synthetic phosphopeptide containing a phosphorylated tyrosine (pY) residue at position 4. This peptide sequence—Glu-Pro-Gln-phosphoTyr-Glu-Glu-Ile-Pro-Ile-Tyr-Leu—is commonly used to study tyrosine phosphorylation-dependent signaling pathways. It mimics motifs recognized by SH2 (Src Homology 2) domains in proteins involved in cellular signal transduction, such as kinases and phosphatases. Researchers use EPQpYEEIPIYL in binding assays, kinase activity studies, and protein interaction profiling to elucidate the roles of tyrosine phosphorylation in processes like cell growth, differentiation, and oncogenesis. Its defined structure makes it a valuable tool in phosphoproteomics and cancer research.