Tyrosine-protein kinase Lyn (LynB) (LynB)

Tyrosine-protein kinase Lyn (LynB) is a member of the Src family of non-receptor tyrosine kinases, primarily expressed in hematopoietic cells such as B-cells, myeloid cells, and mast cells (UniProt P07948). It exists as two isoforms, LynA (56 kDa) and LynB (53 kDa), produced through alternative splicing of exon 2; LynB is the shorter variant lacking a 21-amino acid segment in its unique domain (PubMed: 17438056). Lyn plays a dual role in signal transduction, acting as both a positive and negative regulator of cell surface receptor signaling, particularly the B-cell receptor (BCR) and the high-affinity IgE receptor (FcεRI) (PubMed: 25631201). In oncology, Lyn is frequently overexpressed or hyperactivated in various hematologic malignancies, including chronic myeloid leukemia (CML) and acute myeloid leukemia (AML), where it contributes to drug resistance against BCR-ABL inhibitors like imatinib (PubMed: 15534371). Consequently, Lyn is a significant therapeutic target for multi-kinase inhibitors like dasatinib and bosutinib (DrugBank DB01254). Beyond cancer, its involvement in inflammatory and allergic responses makes it a target of interest for autoimmune and mast cell-related disorders (PubMed: 21169517).

Other names

LYNp53LynJTK8Tyrosine-protein kinase Lyn isoform 2v-yes-1 Yamaguchi sarcoma viral related oncogene homolog

ATP-competitive inhibition of the tyrosine kinase domain, preventing the phosphorylation of downstream substrates in oncogenic and inflammatory signaling pathways.