Parathyroid hormone fragment [3-34] stimulates protein kinase C (PKC) activity in rat osteosarcoma and murine T-lymphoma cells.

The parathyroid hormone (PTH) fragment [1-34] strongly stimulated both adenylate cyclase and membrane-associated PKC activities in rat 17/2 osteosarcoma cells. By contrast, the PTH [3-34] fragment, which was unable to stimulate adenylate cyclase, remained a potent stimulator of membrane-associated PKC activity in these cells. Both PTH fragments also strongly stimulated membrane-PKC activity in cyc-S49T-lymphoma cells possessing a defective adenylate cyclase system. This ability of PTH [3-34] to stimulate membrane-associated PKC activity could explain the residual bioactivity of this fragment.