The complex role of phosphodiesterase 6 in rod photoreceptor health and function

磷酸二酯酶 6 在视杆光感受器健康和功能中的复杂作用

• 批准号: 10662478
• 负责人: Krzysztof Palczewski
• 金额: $ 62.95万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10662478
• 关键词: 3-Dimensional; Affect; Allosteric Regulation; Architecture; Binding; Biochemical; Biological; Brain; Catalytic Domain; Complex; Cryo-electron tomography; Cryoelectron Microscopy; Cyclic GMP; Data; Defect; Development; Dimensions; Disease; Disparate; Electrons; Elements; Enzymes; Equilibrium; Event; G Protein-Coupled Receptor Signaling; Genes; Goals; Guanosine Triphosphate; Health; Heterozygote; Human; Hydrolase; Individual; Inherited; Isoenzymes; Knowledge; Life; Light; Link; Liposomes; Maintenance; Mediating; Membrane; Molecular; Molecular Conformation; Mus; Mutation; N-terminal; Neurons; Photoreceptors; Phototransduction; Play; Process; Proteins; Regulation; Research; Resolution; Retina; Retinal Degeneration; Retinal Dystrophy; Retinal Photoreceptors; Retinal Pigments; Retinoids; Rod Outer Segments; Role; Signal Transduction; Structural Protein; Structure; Tail; Technology; Therapeutic; Tomogram; Visualization; algorithm training; data acquisition; density; disease-causing mutation; inhibitor; nanometer; neural network; novel therapeutics; peripherin; phosphodiesterase 6; photoreceptor degeneration; reconstruction; retinal rods; rod outer segment disc; virtual; visual phototransduction

ABSTRACT Retinal photoreceptor cells can respond to light throughout an individual’s life due to continuous resetting of the light sensing molecules (visual pigments) and their associated signaling elements. Defects in almost all proteins involved in these processes cause photoreceptor degeneration, which could result not only from a deficiency in enzymatic or other functional activity, but also from a loss of structural elements that maintain the complex topology of the rod outer segment (ROS). Our long-term goal is to elucidate the molecular mechanisms of phototransduction and retinal degeneration to promote the discovery of therapeutics for inherited blinding diseases in humans caused by mutations in phototransduction genes. Mutations in the gene encoding phosphodiesterase 6 (PDE6) are among the main causes of such diseases. Accordingly, we propose two thematically and experimentally linked specific aims. Aim 1: Determine the high- resolution structure of rod outer segments (ROS) and rim region of individual disks derived from three- dimensional (3D) cryo-electron tomograms. This aim has been subdivided into three sub-aims that will focus on determining the molecular identity of the spacers that hold disks precisely arranged, determining the structure of ROS with reduced levels of PDE6 and its impact on ROS organization and the number of pillars, and determining the structure of ROS disk rims and the role of ABCA4 on ROS structural integrity. This research will advance our understanding of the function of PDE6 not only as an enzyme but also as a structural protein. Aim 2: Define the role of the N-terminal pony-tail helical region and delineate the allosteric regulation of PDE6. This aim has been subdivided into three sub-aims that will focus on the membrane anchoring role of the Pt-motif, elucidating the allosteric activation mechanism of the PDE6αβγ2 complex, and determining the structure of the Gtα-GTP-PDE6αβγ2 complex. Overall, the findings from this proposal will facilitate the development of a rational approach to alleviate retinal dystrophies related to mutations in the PDE6 gene.

抽象的 由于视网膜感光细胞的不断重置，视网膜感光细胞可以在人的一生中对光做出反应。 光传感分子（视觉色素）及其相关信号元件。几乎所有蛋白质都存在缺陷 参与这些过程会导致光感受器变性，这不仅可能是由于缺乏 酶或其他功能活性，但也来自维持复合物的结构元件的损失 杆外节（ROS）的拓扑结构。我们的长期目标是阐明其分子机制 光转导和视网膜变性促进遗传性致盲疗法的发现 由光转导基因突变引起的人类疾病。基因编码突变 磷酸二酯酶 6 (PDE6) 是此类疾病的主要原因之一。 因此，我们提出了两个主题和实验相关的具体目标。目标 1：确定高 杆外段（ROS）的分辨率结构和来自三层的单个圆盘的边缘区域 三维（3D）冷冻电子断层扫描。该目标已细分为三个子目标，重点关注 确定精确排列圆盘的间隔物的分子身份，确定结构 PDE6 水平降低的 ROS 及其对 ROS 组织和支柱数量的影响，以及 确定 ROS 盘边缘的结构以及 ABCA4 对 ROS 结构完整性的作用。这项研究将 增进我们对 PDE6 功能的理解，不仅作为一种酶，而且作为一种结构蛋白。目的 图 2：定义 N 末端马尾螺旋区域的作用并描述 PDE6 的变构调节。 该目标已细分为三个子目标，重点关注 Pt 基序的膜锚定作用， 阐明PDE6αβγ2复合物的变构激活机制，并确定其结构 Gtα-GTP-PDE6αβγ2 复合物。总体而言，该提案的调查结果将有助于制定合理的 缓解与 PDE6 基因突变相关的视网膜营养不良的方法。

项目成果

Determinants shaping the nanoscale architecture of the mouse rod outer segment.

• DOI: 10.7554/elife.72817
• 发表时间: 2021-12-21
• 期刊: eLife
• 影响因子: 7.7
• 作者: Pöge M;Mahamid J;Imanishi SS;Plitzko JM;Palczewski K;Baumeister W
• 通讯作者: Baumeister W

VCP/p97 inhibitor CB-5083 modulates muscle pathology in a mouse model of VCP inclusion body myopathy.

• DOI: 10.1186/s12967-021-03186-6
• 发表时间: 2022-01-08
• 期刊: Journal of translational medicine
• 影响因子: 7.4
• 作者: Cheng C;Weiss L;Leinonen H;Shmara A;Yin HZ;Ton T;Do A;Lee J;Ta L;Mohanty E;Vargas J;Weiss J;Palczewski K;Kimonis V
• 通讯作者: Kimonis V

New focus on regulation of the rod photoreceptor phosphodiesterase.

• DOI: 10.1016/j.sbi.2021.03.016
• 发表时间: 2021-08
• 期刊: Current opinion in structural biology
• 影响因子: 6.8
• 作者: Gulati S;Palczewski K
• 通讯作者: Palczewski K

Chromophore hydrolysis and release from photoactivated rhodopsin in native membranes.

• DOI: 10.1073/pnas.2213911119
• 发表时间: 2022-11-08
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Hong, John D.;Salom, David;Kubas, Adam;Kiser, Philip D.;Palczewski, Krzysztof
• 通讯作者: Palczewski, Krzysztof

Effective gene therapy of Stargardt disease with PEG-ECO/pGRK1-ABCA4-S/MAR nanoparticles.

使用PEG-ECO/PGRK1-ABCA4-S/MAR纳米颗粒的Stargardt疾病的有效基因治疗。

• DOI: 10.1016/j.omtn.2022.08.026
• 发表时间: 2022-09-13
• 期刊: MOLECULAR THERAPY NUCLEIC ACIDS
• 作者: Sun, Da;Sun, Wenyu;Gao, Song-Qi;Lehrer, Jonathan;Naderi, Amirreza;Wei, Cheng;Lee, Sangjoon;Schilb, Andrew L.;Scheidt, Josef;Hall, Ryan C.;Traboulsi, Elias I.;Palczewski, Krzysztof;Lu, Zheng-Rong
• 通讯作者: Lu, Zheng-Rong