Nuclear transport of parathyroid hormone (PTH)-related protein is dependent on microtubules

Abstract

PTH-related protein (PTHrP) was first discovered as a circulating factor secreted by certain cancers and is responsible for the syndrome of humoral hypercalcemia of malignancy induced by various tumors. The similarity of its N terminus to that of PTH enables PTHrP to share the signaling properties of PTH, but the rest of the molecule possesses distinct functions, including a role in the nucleus/nucleolus in reducing apoptosis and enhancing cell proliferation. PTHrP nuclear import is mediated by importin β1. In this study we use the technique of fluorescence recovery after photobleaching to demonstrate the ability of PTHrP to shuttle between cytoplasm and nucleus and to visualize directly the..