Sakagami Hiroyuki, Katsumata Osamu, Hara Yoshinobu, Tamaki Hideaki, Fukaya Masahiro
Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0374, Japan.
Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0374, Japan.
Brain Res. 2014 Oct 24;1586:23-33. doi: 10.1016/j.brainres.2014.08.051. Epub 2014 Aug 22.
Type I phosphatidylinositol 4-phosphate 5 kinase γ (PIP5KIγ) constitutes a major pathway for the generation of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) that regulates a variety of neuronal functions at both presynaptic and postsynaptic compartments. In this study, we examined the expression and localization of PIP5KIγ in the adult mouse retina. RT-PCR analysis revealed that PIP5KIγ_v2 was predominantly expressed in the retina while PIP5KIγ_v3 was also expressed faintly. Immunostaining of the adult mouse retina revealed intense PIP5KIγ-immunoreactivity in the inner and outer plexiform layers in a punctate manner. In the photoreceptor ribbon synapse, PIP5KIγ was highly concentrated at the periactive zone. These findings suggest that PIP5KIγ, especially PIP5KIγ_i2, is localized at the periactive zone, a functionally suitable compartment for the endocytosis of synaptic vesicles in photoreceptor ribbon synapses.
I型磷脂酰肌醇4-磷酸5激酶γ（PIP5KIγ）构成了生成磷脂酰肌醇4,5-二磷酸（PtdIns(4,5)P2）的主要途径，该途径在突触前和突触后区室调节多种神经元功能。在本研究中，我们检测了PIP5KIγ在成年小鼠视网膜中的表达和定位。RT-PCR分析显示，PIP5KIγ_v2在视网膜中主要表达，而PIP5KIγ_v3也有微弱表达。成年小鼠视网膜的免疫染色显示，在内、外网状层中PIP5KIγ免疫反应性呈点状强烈表达。在光感受器带状突触中，PIP5KIγ高度集中在活动区周围。这些发现表明，PIP5KIγ，尤其是PIP5KIγ_i2，定位于活动区周围，这是光感受器带状突触中突触小泡内吞作用在功能上合适的区室。
