SYNAPTOJANIN-1 - LOCALIZATION ON COATED ENDOCYTIC INTERMEDIATES IN NERVE-TERMINALS AND INTERACTION OF ITS 170 KDA ISOFORM WITH EPS15

Synaptojanin 1 is an inositol 5-phosphatase with a putative role in cl athrin-mediated endocytosis, Goal of this study was to provide new evi dence for this hypothesis, We show that synaptojanin 1 is concentrated at clathrin-coated endocytic intermediates in nerve terminals, Furthe rmore, we report that synaptojanin-170, an alternatively spliced isofo rm of synaptojanin I, binds Eps15, a clathrin coat-associated protein, Binding is mediated by the COOH-terminal region of synaptojanin-170 w hich we show here to be poorly conserved from rat to humans, but to co ntain in both species three asparagine-proline-phenylalanine (NPF) rep eats, This motif has been found to be the core of the binding site for the EH domains of Eps15, Together with previous data, our results sug gest that synaptojanin 1 can be recruited to clathrin-coated pits via a multiplicity of interactions. (C) 1997 Federation of European Bioche mical Societies.