REGENERATING PERIPHERAL-NERVES RELEASE A DIFFUSABLE PROTEIN-KINASE

Using [gamma-P-32]ATP and 1-dimensional electrophoresis this report sh ows that a protein kinase is released in the culture medium from adult frog sciatic nerves during regeneration in vitro. The kinase, which p hosphorylated serine and to some extent threonine residues, was releas ed from non-neuronal cells. It showed an increased activity during the 3rd to 6th day after injury, coinciding with the injury induced proli feration of non-neuronal cells. When the proliferation was inhibited b y a mitotic agent, the activity of the protein kinase was lowered, fur ther linking it to the division of cells.