Xu Y S, Kantorow M, Davis J, Piatigorsky J
Laboratory of Molecular and Developmental Biology, NEI, National Institutes of Health, Bethesda, Maryland 20892-2730, USA.
J Biol Chem. 2000 Aug 11;275(32):24645-52. doi: 10.1074/jbc.M001159200.
We have shown that gelsolin is one of the most prevalent water-soluble proteins in the transparent cornea of zebrafish. There are also significant amounts of actin. In contrast to actin, gelsolin is barely detectable in other eye tissues (iris, lens, and remaining eye) of the zebrafish. Gelsolin cDNA hybridized intensely in Northern blots to RNA from the cornea but not from the lens, brain, or headless body. The deduced zebrafish gelsolin is approximately 60% identical to mammalian cytosolic gelsolin and has the characteristic six segmental repeats as well as the binding sites for actin, calcium, and phosphatidylinositides. In situ hybridization tests showed that gelsolin mRNA is concentrated in the zebrafish corneal epithelium. The zebrafish corneal epithelium stains very weakly with rhodamine-phalloidin, indicating little F-actin in the cytoplasm. In contrast, the mouse corneal epithelium contains relatively little gelsolin and stains intensely with rhodamine-phalloidin, as does the zebrafish extraocular muscle. We propose, by analogy with the diverse crystallins of the eye lens and with the putative enzyme-crystallins (aldehyde dehydrogenase class 3 and other enzymes) of the mammalian cornea, that gelsolin and actin-gelsolin complexes act as water-soluble crystallins in the zebrafish cornea and contribute to its optical properties.
我们已经证明，凝溶胶蛋白是斑马鱼透明角膜中最普遍的水溶性蛋白质之一。其中也存在大量肌动蛋白。与肌动蛋白不同，在斑马鱼的其他眼组织（虹膜、晶状体和其余眼部组织）中几乎检测不到凝溶胶蛋白。在Northern印迹中，凝溶胶蛋白cDNA与来自角膜而非晶状体、大脑或无头身体的RNA强烈杂交。推导得出的斑马鱼凝溶胶蛋白与哺乳动物胞质凝溶胶蛋白约60%相同，具有特征性的六个节段重复序列以及肌动蛋白、钙和磷脂酰肌醇的结合位点。原位杂交试验表明，凝溶胶蛋白mRNA集中在斑马鱼角膜上皮中。斑马鱼角膜上皮用罗丹明-鬼笔环肽染色非常浅，表明细胞质中F-肌动蛋白很少。相比之下，小鼠角膜上皮中凝溶胶蛋白相对较少，用罗丹明-鬼笔环肽染色强烈，斑马鱼眼外肌也是如此。我们通过与晶状体的多种晶状体蛋白以及哺乳动物角膜的假定酶晶状体蛋白（3类醛脱氢酶和其他酶）进行类比，提出凝溶胶蛋白和肌动蛋白-凝溶胶蛋白复合物在斑马鱼角膜中作为水溶性晶状体蛋白起作用，并有助于其光学特性。
