UV-light-dependent binding of a visual arrestin 1 isoform to photoreceptor membranes in a neuropteran (Ascalaphus) compound eye

Arrestins are regulators of the active state of G-protein-coupled receptors. Towards elucidating the function of different arrestin subfamilies in sensory cells, we have isolated a novel arrestin 1, Am Arr1, from the UV photoreceptors of the neuropteran Ascalaphus macaronius. Am Arr1 forms a phylogenetic clade with antennal and visual Arr1 isoforms of invertebrates. Am Arr1 undergoes a light-dependent binding cycle to photoreceptor membranes, as reported earlier only for members of the arrestin 2 subfamily. This suggests a common control mechanism for the active state of invertebrate rhodopsins and G-protein-coupled receptors of antennal sensory cells. Furthermore, it implies that a strict correlation of distinct arrestin isoforms to distinct functions is not a general principle for invertebrate sensory cells.