mGK-6-derived true tissue kallikrein is synthesized, processed, and targeted through a regulated secretory pathway in...

mGK-6-derived true tissue kallikrein was shown to be synthesized in mouse pituitary AtT-20 cells. This cell line, which is capable of processing other prohormones, only partially processed the proform of kallikrein to its active form, secreting it predominantly as the proform. The secretion of the active form was stimulated in response to a secretagogue, 8-bromo-cyclic AMP. These results imply that not only cellular elements capable of directing the processing of the proform to the active form and the intracellular transport of the kallikrein, but also a pathway that regulates the release of the active form may be present in the AtT-20 cells, thus the availability of this cell line for investigation of biosynthetic and secretory processes for tissue kallikrein in vivo being suggested.