... the shutting-down of the downstream signaling [1–4]. Vertebrate arrestins can be divided into two classes; visual arrestins and nonvisual, b -arrestins. Visual arrestins arecomposed of rod- and cone -arrestins, ... ahypothesis that Ci-Arr is the prototype of vertebrate arrestin and that in the evolutionary process to vertebrates the duplication of the prototype resulted in two different types of arrestins, visual ... PRIORITY PAPER Ascidian arrestin (Ci-arr), the origin of the visual and nonvisual arrestins of vertebrate Masashi Nakagawa1, Hidefumi Orii1, Norihiro Yoshida2, Eri Jojima3,...