ROLE OF PHOSPHORYLATION IN REGULATION OF THE ASSEMBLY OF ENDOCYTIC COAT COMPLEXES

Clathrin-mediated endocytosis involves cycles of assembly and disassem bly of clathrin coat components and their accessory proteins. Dephosph orylation of rat brain extract was shown to promote the assembly of dy namin 1, synaptojanin 1, and amphiphysin into complexes that also incl uded clathrin and AP-2, Phosphorylation of dynamin 1 and synaptojanin 1 inhibited their binding to amphiphysin, whereas phosphorylation of a mphiphysin inhibited its binding to AP-2 and clathrin. Thus, phosphory lation regulates the association and dissociation cycle of the clathri n-based endocytic machinery, and calcium-dependent dephosphorylation o f endocytic proteins could prepare nerve terminals for a burst of endo cytosis.