Abstract: Methods are disclosed herein for modulating osteoclast fusion. In some embodiments, these methods include administering an effective amount of a Lupus autoantigen (La) protein, or an agent that modulates La protein expression or activity, to a subject in need thereof, thereby modulating osteoclast fusion in the subject. In some embodiments, the method increases osteoclast fusion and bone resorption. In other embodiments, the method decreases osteoclast fusion and bone resorption.

Abstract: Some embodiments of the invention include polypeptides comprising a myomerger polypeptide or an extracellular myomerger polypeptide. Other embodiments of the invention include nucleic acid molecules encoding polypeptides comprising a myomerger polypeptide or an extracellular myomerger polypeptide. Other embodiments of the invention include vectors comprising the nucleic acid molecule. Yet other embodiments of the invention include methods of using a myomerger polypeptide or an extracellular myomerger polypeptide. Additional embodiments of the invention are also discussed herein.