cDNA cloning and nuclear localization of the circadian neuropeptide designated as pigment-dispersing factor PDF in the cricket Gryllus bimaculatus.
cDNA cloning and nuclear localization of the circadian neuropeptide designated as pigment-dispersing factor PDF in the cricket Gryllus bimaculatus.
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蟋蟀双斑蝼蛄昼夜节律神经肽（称为色素分散因子 PDF）的 cDNA 克隆和核定位。
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
M. Shimohigashi
中科院分区：
文献类型：
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作者：
Y. Chuman;A. Matsushima;Seiji Sato;K. Tomioka;Y. Tominaga;I. Meinertzhagen;Y. Shimohigashi;M. Shimohigashi
最近报道称色素分散因子（PDF）是一种主要的昼夜节律神经调节剂，参与传递昆虫日常运动的昼夜节律。在果蝇中，PDF在一些表达时钟基因period、timeless、Clock和cycle的神经元中发挥作用，而这些时钟基因反过来又调节pdf基因的表达。在本研究中，我们在夜行性昆虫蟋蟀 Gryllus bimaculatus 的大脑中克隆了编码 PDF 的 cDNA，并发现一个分离的克隆（310 bp）编码一种非常短的前体蛋白，没有明确的信号序列，而是类似核定位信号（NLS）的序列。蟋蟀 PDF 与昆虫 PDF 以及甲壳类动物 β-PDH 肽具有较高的序列同一性 (78-94%) 和相似性 (89-100%)。在 G. bimaculatus 的视叶中，髓质和椎板神经桩中都有 PDF 免疫反应性神经元。在强烈免疫反应性的层 PDF 神经元中，在电子显微镜下我们发现细胞表现出不同的染色，不仅是细胞质，而且是细胞核。当 GFP 融合的 PDF 前体蛋白在 COS-7 细胞中表达时，观察到融合蛋白明显易位到细胞核中。这是在细胞核中首次发现 PDF 肽，这表明 PDF 肽本身在生物钟系统中具有重要作用。
Pigment-dispersing factor (PDF) was recently reported to be a principal circadian neuromodulator involved in transmitting circadian rhythms of daily locomotion in insects. In Drosophila, PDF functions in some of the neurons expressing the clock genes period, timeless, Clock, and cycle, and those clock genes in turn regulate pdf gene expression. In the present study, we cloned a cDNA encoding PDF in the brain of a nocturnal insect, the cricket Gryllus bimaculatus, and found that an isolated clone (310 bp) codes for an extraordinarily short precursor protein with no definite signal sequence, but a nuclear localization signal (NLS)-like sequence instead. The cricket PDF exhibits high sequence identity (78-94%) and similarity (89-100%) to insect PDFs and also to crustacean beta-PDH peptides. In the optic lobes of G. bimaculatus there are PDF-immunoreactive neurons in both the medulla and lamina neuropiles. Among the strongly immunoreactive lamina PDF neurons, on electron microscopy we identified cells exhibiting distinct staining that is not only cytoplasmic but also nuclear. When GFP-fused PDF precursor proteins were expressed in COS-7 cells, distinct translocation of the fusion protein into the nucleus was observed. This is the first finding of PDF peptide in the nucleus, which suggests a fundamental role of PDF peptide per se in the circadian clock system.