THE PHOSPHATIDYLINOSITOL-BINDING SITE OF MICROTUBULE-ASSOCIATED PROTEIN MAP2

Recent evidence [Surridge and Burns, Biochemistry (1994) 33, 8051-8057 ] on the interaction of native and recombinant tau, recombinant MAP2c, and native MAP2 with vesicles prepared from phosphatidylinositol (Ptd Ins) and other phospholipids demonstrate that MAP2 differs from MAP2c and from tau in having a high-affinity PtdIns-binding site. The locati on of this site within the MAP2-specific insert peptide, coupled with considerations of the nature of the MAP2 tubulin-binding site, suggest s that PtdIns-binding induces a conformational change which alters the MAP2 tubulin-binding domain. Furthermore, the restricted cellular dis tribution of MAP2 implies that the MAP2:PtdIns interaction may play a central role in modulating the dendritic cytoskeleton.