Opsins are a class of light sensitive G-protein coupled receptors (GPCRs) involved in both visual and non-visual responses to light. While the function and activation mechanisms of the visual opsins are well understood, the function of non-visual opsins is less clear. Opsin 3, or OPN3, is a non-visual opsin expressed in many tissues, including the brain, and was recently found by the Oancea lab at Brown to be expressed in human skin cells. Furthermore, OPN3 has an elongated C-terminus relative to the other opsins that does not have homology to any other opsin or GPCR. The function and activation mechanism of OPN3 are currently unknown in any tissue, and its subcellular localization is also unknown. As the subcellular localization of the protein will significantly impact its function, it is crucial to know in investigating the function of OPN3. To investigate the subcellular localization of OPN3, fluorescent constructs of both the full-length OPN3 protein and the unique C-terminal region were made and transfected into MeWo melanocyte cells. Most GPCRs show plasma membrane localization, but the full-length OPN3 construct instead show intracellular localization, in a perinuclear region resembling Golgi. Interestingly, the unique C-terminal region of OPN3 showed plasma membrane and intracellular vesicular localization as would be expected from most GPCRs, suggesting that the transmembrane region is responsible for the intracellular localization of the full-length protein. These data provide a foundation for beginning to understand the function of OPN3 in a native context.
Dushko, Margaret,
"Localization of human opsin 3 (OPN3) in human epidermal melanocytes"
(2014).
Summer Research Symposium.
Brown Digital Repository. Brown University Library.
https://doi.org/10.26300/hkms-fa74
Each year, Brown University showcases the research of its undergraduates at the Summer Research Symposium. More than half of the student-researchers are UTRA recipients, while others receive funding from a variety of Brown-administered and national programs and fellowships and go …
