Crow Terry, Xue-Bian J J
Department of Neurobiology and Anatomy, University of Texas Medical School, Houston, Texas 77225, USA.
J Neurosci. 2002 Dec 15;22(24):10514-8. doi: 10.1523/JNEUROSCI.22-24-10514.2002.
Hermissenda CSP24 (cytoskeletal-related protein 24) is a 24 kDa beta-thymosin-like protein that is associated with intermediate memory. We showed previously that one-trial conditioning resulted in a significant increase in the phosphorylation of CSP24 detected in lysates of the pathway supporting the conditioned stimulus (CS). Here we report the association of the protein with the actin cytoskeleton and the distribution of CSP24-immunoreactive neurons in two sensory structures and the circumesophageal nervous system. Identified photoreceptors, hair cells, and neurons in the cerebropleural and pedal ganglia were immunoreactive for CSP24. Immunoprecipitation experiments with 32PO4-labeled lysates of the circumesophageal nervous system identified a 44 kDa protein band (consistent with actin) that coprecipitates with CSP24. An analysis of immunoprecipitates on Western blots probed with anti-actin antibody also showed that actin coprecipitates with CSP24. Laser confocal microscopy of photoreceptors costained with fluorescently labeled anti-actin antibody and anti-CSP24 antibody, or fluorescent phalloidin and anti-CSP24 antibody showed that CSP24 is localized with actin in the cytosol of photoreceptor cell bodies and colocalized with presumed G-actin, but not F-actin, in regions adjacent to the plasma membrane. Although CSP24 is widely distributed in the Hermissenda nervous system, its regulation by one-trial conditioning was observed only in the CS pathway. Our findings suggest that CSP24 may interact with components of the actin cytoskeleton that contribute to structural changes underlying the formation and maintenance of enduring forms of memory.
海兔CSP24（细胞骨架相关蛋白24）是一种24 kDa的β-胸腺素样蛋白，与中间记忆有关。我们之前表明，单次训练会导致在支持条件刺激（CS）的通路裂解物中检测到的CSP24磷酸化显著增加。在此，我们报告该蛋白与肌动蛋白细胞骨架的关联，以及CSP24免疫反应性神经元在两个感觉结构和食管周围神经系统中的分布。已鉴定的光感受器、毛细胞以及脑胸膜和足神经节中的神经元对CSP24呈免疫反应性。用32PO4标记的食管周围神经系统裂解物进行免疫沉淀实验，鉴定出一条与CSP24共沉淀的44 kDa蛋白带（与肌动蛋白一致）。用抗肌动蛋白抗体探测的免疫沉淀蛋白印迹分析也表明肌动蛋白与CSP24共沉淀。用荧光标记的抗肌动蛋白抗体和抗CSP24抗体或荧光鬼笔环肽和抗CSP24抗体对光感受器进行激光共聚焦显微镜观察，结果显示CSP24定位于光感受器细胞体胞质溶胶中的肌动蛋白上，并在质膜附近区域与推测的G-肌动蛋白共定位，但不与F-肌动蛋白共定位。尽管CSP24广泛分布于海兔神经系统中，但其受单次训练调节的情况仅在CS通路中观察到。我们的研究结果表明，CSP24可能与肌动蛋白细胞骨架的成分相互作用，这些成分有助于形成和维持持久记忆形式的潜在结构变化。
