Lyn

Lyn is a Src-family tyrosine kinase that relays immune-cell receptor inputs to regulate proliferation, differentiation, apoptosis, migration, and metabolism[1]. Mechanistically, Lyn phosphorylates ITAM and ITIM signaling motifs, enabling both activating and inhibitory immunoreceptor signaling[1][2]. In B-cell biology, Lyn negatively regulates B-cell receptor signaling, and loss of Lyn in B cells leads to lupus-like autoimmunity in mouse models[3]. Compared with related Lyn isoforms, LynB shows a dominant immunosuppressive function in vivo, whereas LynA is uniquely required to restrain autoimmunity in female mice[4]. For experimental applications, bafetinib/NS-187 is a dual Bcr-Abl/Lyn tyrosine kinase inhibitor used in imatinib-resistant leukemia research[5]. MLR-1023 is an allosteric Lyn kinase activator and insulin receptor potentiator used in glucose-homeostasis models[6].