LOCALIZATION OF GUANYLATE CYCLASE ACTIVATING PROTEIN 2 IN MAMMALIAN RETINAS

鸟苷酸环化酶激活蛋白 2 在哺乳动物视网膜中的定位

• 批准号: 6277631
• 负责人: KRZYSZTOF PALCZEWSKI
• 金额: $ 7.23万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6277631
• 关键词: Primates; animal tissue; eye; human tissue; microscopy; nervous system; proteins

When the eyes of vertebrate animals have been exposed to light and then the light is extinguished, rod photoreceptors in the neural retina must re-establish a dark-adapted state. A critical step in this process is the intracellular stimulation of the enzyme guanylate cyclase (GC). GC-activating proteins (GCAP1 and GCAP2) modulate GC activation. GCAP activation of GC is regulated by the concentration of intracellular calcium ions [Ca2+]i. Previous studies have localized GCAP1 to rod and cone outer segments, somata and synaptic terminals. In the current study, we used in situ hybridization and immunocytochemistry to localize GCAP2 in human, monkey, and bovine retinas. In human and monkey retinas, the most intense immunolabeling with anti-GCAP2 antibodies was in the cone inner segments, somata and synaptic terminals and, to a lesser degree, in the rod inner segments and inner retinal neurons. In bovine retinas, the most intense immunolabeling was in the rod inner segments, with weaker labeling of cone myoids, somata and synapses. Additional enzymatic assays using a GCAP2-specific antibody confirmed that GCAP1, but not GCAP2, is the major component that stimulates GC in bovine rod outer segments. These results suggest that although GCAP1 is involved in the Ca2+-sensitive regulation of GC in rod and cone outer segments, GCAP2 may have non-phototransduction functions in photoreceptors and inner retinal neurons. Although the role of GCAP1 and GCAP2 mutations in human retinal diseases has yet to be established, mutations in GC are known to cause a severe retinopathy known as Leber's congenital amaurosis. Individuals with loss of function mutations in GCAPs might be expected to exhibit a similar phenotype.

当脊椎动物的眼睛暴露在光线下， 然后光线熄灭，神经细胞中的杆状光感受器 视网膜必须重新建立暗适应状态。 的关键步骤 这个过程是鸟苷酸酶的细胞内刺激 环化酶（GC）。 GC激活蛋白（GCAP 1和GCAP 2）调节GC activation. GC的GCAP激活受浓度调节 细胞内钙离子[Ca2+]i. 先前的研究 GCAP 1定位于视杆和视锥外节、胞体和突触， terminals. 在目前的研究中，我们使用原位杂交技术， 免疫细胞化学在人、猴和牛中定位GCAP 2 视网膜 在人类和猴子的视网膜中， 与抗GCAP 2抗体在锥体内节，胞体和 突触终末和，在较小程度上，在杆内段 和内部视网膜神经元。 在牛视网膜中， 免疫标记位于视杆内节， 视锥肌样细胞、胞体和突触。 另外的酶测定使用 GCAP2特异性抗体证实GCAP1而不是GCAP2是GCAP2的特异性抗体。 刺激牛视杆外节GC的主要成分。 这些结果表明，虽然GCAP 1参与了 视杆细胞和视锥细胞外节GC的Ca 2+敏感性调节 可能在光感受器和内部具有非光转导功能 视网膜神经元 虽然GCAP 1和GCAP 2突变在 人类视网膜疾病尚未建立，GC突变是 会导致严重的视网膜病变，称为利伯氏先天性视网膜病变 黑蒙 GCAP功能缺失突变的个体可能 预期会表现出相似的表型。