DLK (Dual Leucine Zipper-Bearing Kinase)
DLK is a serine/threonine kinase that belongs to the mixed-lineage kinase (MLK) family of mitogen-activated protein kinase kinase kinases (MAPKKKs) (Gallo and Johnson 2002). It was discovered in 1994 as a protein differentially expressed during the retinoic-acid-induced neuronal differentiation of human NT2 teratocarcinoma cells and originally denoted zipper protein kinase (ZPK, Reddy and Pleasure 1994). Parallel and subsequent studies led to the identification and cloning of the mouse and rat homologs of ZPK, respectively termed DLK (Holzman et al. 1994) and MAP kinase upstream kinase (MUK, Hirai et al. 1996).
Structure, Expression, and Subcellular Localization
We thank the Natural Sciences and Engineering Research Council of Canada for its financial support. We also apologize to our colleagues whose work could not be cited due to space limitations.