Expression patterns of protein kinase D 3 during mouse development

Background: The PKD family of serine/threonine kinases comprises a single member in Drosophila (dPKD), two isoforms in C. elegans (DKF-1 and 2) and three members, PKD1, PKD2 and PKD3 in mammals. PKD1 and PKD2 have been the focus of most studies up to date, which implicate these enzymes in very diverse cellular functions, including Golgi organization and plasma membrane directed transport, immune responses, apoptosis and cell proliferation. Concerning PKD3, a role in the formation of vesicular transport carriers at the trans-Golgi network (TGN) and in basal glucose transport has been inferred from in vitro studies. So far, however, the physiological functions of the kinase during development remain unknown. Results: We have examined the expression pattern of PKD3 during the development of mouse embryos by immunohistochemistry. Using a PKD3 specific antibody we demonstrate that the kinase is differentially expressed during organogenesis. In the developing heart a strong PKD3 expression is constantly detected from E10 to E16.5. From E12.5 on PKD3 is increasingly expressed in neuronal as well as in the supporting connective tissue and in skeletal muscles. Conclusion: The data presented support an important role for PKD3 during development of these tissues.