Ohbayashi N, Hoshikawa M, Kimura S, Yamasaki M, Fukui S, Itoh N
Department of Genetic Biochemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo, Kyoto 606-8501, Japan.
J Biol Chem. 1998 Jul 17;273(29):18161-4. doi: 10.1074/jbc.273.29.18161.
We isolated the cDNA encoding a novel member (207 amino acids) of the fibroblast growth factor (FGF) family from rat embryos. Because this protein is the 18th documented member of the FGF family, we tentatively termed it FGF-18. We have also determined mouse and human FGF-18 with high amino acid identity (99.5 and 99.0%) to rat FGF-18, respectively. Among FGF family members, FGF-18 is most similar (52.7% amino acid identity) to FGF-8 and FGF-17. FGF-18 has a typical signal sequence at its amino terminus. Recombinant rat FGF-18, which was efficiently secreted by High Five insect cells infected with recombinant baculovirus containing the cDNA, induced neurite outgrowth in PC12 cells. The expression of FGF-18 mRNA was examined in adult rat tissues and embryos by Northern blotting analysis and in situ hybridization. FGF-18 mRNA of approximately 2. 7 kilobases was preferentially detected in the lung among adult rat tissues examined. In rat embryos, FGF-18 mRNA was detected in several discrete regions at embryonic days 14.5 and 19.5 but not at E10.5. The temporal and spatial patterns of FGF-18 mRNA expression in embryos are quite different from those of FGF-8 and FGF-17 mRNAs reported. The present results indicate that FGF-18 is a unique secreted signaling molecule in the adult lung and developing tissues.
我们从大鼠胚胎中分离出了编码成纤维细胞生长因子（FGF）家族一个新成员（207个氨基酸）的cDNA。由于该蛋白是FGF家族中第18个被记录的成员，我们暂时将其命名为FGF-18。我们还确定了小鼠和人FGF-18，它们与大鼠FGF-18的氨基酸同源性分别高达99.5%和99.0%。在FGF家族成员中，FGF-18与FGF-8和FGF-17最为相似（氨基酸同源性为52.7%）。FGF-18在其氨基末端有一个典型的信号序列。被含有该cDNA的重组杆状病毒感染的High Five昆虫细胞能有效分泌重组大鼠FGF-18，它可诱导PC12细胞长出神经突。通过Northern印迹分析和原位杂交检测了成年大鼠组织和胚胎中FGF-18 mRNA的表达。在所检测的成年大鼠组织中，在肺中优先检测到了约2.7千碱基的FGF-18 mRNA。在大鼠胚胎中，在胚胎第14.5天和19.5天的几个离散区域检测到了FGF-18 mRNA，但在胚胎第10.5天未检测到。胚胎中FGF-18 mRNA表达的时空模式与已报道的FGF-8和FGF-17 mRNA的时空模式有很大不同。目前的结果表明，FGF-18是成年肺和发育中组织中一种独特的分泌性信号分子。
