During Drosophila phototransduction, the G protein coupled receptor (GPCR) Rhodopsin (Rh1) transduces photon absorption into electrical signal via G-protein coupled activation of phospholipase C (PLC). Rh1 levels in the plasma membrane are critical for normal sensitivity to light. In this study, we report that Protein Kinase D (dPKD) regulates Rh1 homeostasis in adult photoreceptors. Although eye development and retinal structure are unaffected in the dPKD hypomorph (dPKD^H), it exhibited elevated levels of Rh1. Surprisingly, despite having elevated levels of Rh1, no defect was observed in the electrical response to light in these flies. By contrast the levels of another transmembrane protein of the photoreceptor plasma membrane, Transient receptor potential (TRP) was not altered in dPKD^H. Our results indicate that dPKD is dispensable for eye development but is required for maintaining Rh1 levels in adult photoreceptors.

在果蝇光转导过程中，G蛋白偶联受体（GPCR）视紫红质（Rh1）通过G蛋白偶联磷脂酶C（PLC）的活化将光子吸收转化为电信号。质膜中的Rh1水平对于正常的光敏感度至关重要。在这项研究中，我们报告蛋白质激酶D（dPKD）调节成年感光细胞Rh1稳态。尽管眼睛发育和视网膜结构在dPKD亚型（dPKD ^H），其Rh1含量升高。出人意料的是，尽管Rh1水平升高，但这些果蝇对光的电响应没有观察到缺陷。相比之下，光感受器质膜的另一种跨膜蛋白的水平，在dPKD ^H中，瞬态受体电位（TRP）不变。我们的结果表明，dPKD对于眼睛发育是必不可少的，但对于维持成人感光细胞中的Rh1水平则是必需的。