[Ultrastructural visualization of binding and internalization of cholera and tetanuts toxins].

In monolayer cultures of a liver line, a population of non-coated membrane microinvaginations is preferentially involved in both the initial binding and subsequent internalization of colloidal gold-labelled cholera and tetanus toxins. These two toxins thus appear to be internalized via another pathway than most other polypeptide ligands studied, which enter cells via coated plasma membrane invaginations.