Lemur tyrosine kinase (LMTK2) belongs to the protein kinase superfamily and the protein tyrosine kinase family. It contains N-terminal transmembrane helices and a long C-terminal cytoplasmic tail with serine/threonine/tyrosine kinase activity. LMTK2 interacts with several other proteins, such as Inhibitor-2 (Inh2), protein phosphatase-1 (PP1C), p35, and myosin VI. It phosporylates other proteins, and is itself also phosporylated when interacting with cyclin-dependent kinase 5 (cdk5)/p35 complex. LMTK2 is involved in nerve growth factor (NGF)-TrkA signalling, and also plays a critical role in endosomal membrane trafficking. Mouse studies suggest an essential role of this protein in spermatogeness [taken from NCBI Entrez Gene (Gene ID: 22853)].