Crosslinking of ribosomal proteins to RNA in maize ribosomes by UV-B and its effects on translation1[w]
Crosslinking of ribosomal proteins to RNA in maize ribosomes by UV-B and its effects on translation1[w]
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DOI：
10.1104/pp.104.047043
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发表时间：
2004-10-01
期刊：
影响因子：
7.4
通讯作者：
Walbot, V
中科院分区：
文献类型：
--
作者：
Casati, P;Walbot, V
紫外线-B（UV-B）光子可以导致生物分子中的大量细胞损伤，这对于DNA来说是众所周知的。由于RNA与DNA具有相同的紫外吸收光谱，我们研究了这种细胞成分的损伤。在玉米（Zea mays）叶片中，UV-B辐射通过使细胞溶质核糖体蛋白S14、L23 a和L32以及叶绿体核糖体蛋白L29与RNA交联而破坏核糖体。核糖体损伤积累在一天的UV-B暴露与新的蛋白质生产的逐步减少;然而，从头合成的一些核糖体蛋白的UV-B暴露后6小时增加。16小时后，没有UV-B，受损的核糖体被消除，翻译恢复到正常水平。核糖体蛋白S6和S6激酶在UV-B暴露期间被磷酸化;这些修饰与哺乳动物成纤维细胞中核糖体损伤后某些核糖体蛋白的选择性翻译相关，并且可能是玉米中的适应。无论是光合作用，也没有色素水平的影响显着的UV-B，表明所施加的治疗是不是致命的，玉米叶片生理很容易恢复。
Ultraviolet-B (UV-B) photons can cause substantial cellular damage in biomolecules, as is well established for DNA. Because RNA has the same absorption spectrum for UV as DNA, we have investigated damage to this cellular constituent. In maize (Zea mays) leaves, UV-B radiation damages ribosomes by crosslinking cytosolic ribosomal proteins S14, L23a, and L32, and chloroplast ribosomal protein L29 to RNA. Ribosomal damage accumulated during a day of UV-B exposure correlated with a progressive decrease in new protein production; however, de novo synthesis of some ribosomal proteins is increased after 6 h of UV-B exposure. After 16 h without UV-B, damaged ribosomes were eliminated and translation was restored to normal levels. Ribosomal protein S6 and an S6 kinase are phosphorylated during UV-B exposure; these modifications are associated with selective translation of some ribosomal proteins after ribosome damage in mammalian fibroblast cells and may be an adaptation in maize. Neither photosynthesis nor pigment levels were affected significantly by UV-B, demonstrating that the treatment applied is not lethal and that maize leaf physiology readily recovers.