A ROLE FOR THE ACETYLCHOLINE RECEPTOR-INDUCING PROTEIN ARIA IN OLIGODENDROCYTE DEVELOPMENT

ARIA acetylcholine receptor-inducing activity protein, is a member of a family of ligands that includes the Neu differentiation factor, here gulin, and glial growth factor. These ligands all act through one or m ore receptor tyrosine kinases of approximate to 185 kDa. In some condi tions these ligands promote proliferation, whereas in others they indu ce differentiation. ARIA was originally isolated from chick brain on t he basis of its ability to induce synthesis of nicotinic acetylcholine receptors in skeletal muscle. In this paper we show that ARIA is expr essed in the subventricular zone of the rat brain and that it enhances the development of oligodendrocytes from bipotential (O2A) glial prog enitor cells. We have also found that ARIA induces tyrosine phosphoryl ation of a 185-kDa protein in O2A progenitor cells. ARIA does not incr ease bromodeoxyuridine incorporation by oligodendrocytes but is mitoge nic when added to Schwann cells in vitro. Thus, ARIA accelerates the f ormation of oligodendrocytes in vitro and is expressed where it could exercise the same influence in vivo.