Developmental expression of heme oxygenase isozymes in rat brain. Two HO-2 mRNAs are detected.
Developmental expression of heme oxygenase isozymes in rat brain. Two HO-2 mRNAs are detected.
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DOI：
10.1016/s0021-9258(19)39059-3
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发表时间：
1990-05
期刊：
影响因子：
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通讯作者：
Yi Sun;Mitch O. Rotenberg;M. Maines
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文献类型：
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作者：
Yi Sun;Mitch O. Rotenberg;M. Maines
从大鼠脑中分离的 RNA 的印迹杂交显示，从出生前 1 天到成年的所有发育阶段都存在两个 HO-2 同源转录本（1.3 和 1.9 千碱基 (kb)）。两个 HO-2 信息的水平似乎受到发育调节，并且从产前第 1 天到成年期观察到逐渐增加。通过使用源自 5' 端、中间、 1.3-kb mRNA 的大小与睾丸 HO-2 cDNA 的大小基本相同，并且被认为编码 HO-2 蛋白。 1.9-kb mRNA 似乎不太可能代表 1.3-kb mRNA 的前体，因为它也在体内翻译，尽管效率不及两种 HO-2 mRNA。与 HO-2 不同，只能检测到一个约 1.8 kb 的 HO-1 转录物，该转录物的丰度非常低，并且不受细菌内毒素的影响，但使用针对肝脏 HO-1 的抗体进行的蛋白质印迹分析无法检测到该诱导信息的产物。然而，使用相同的抗体可以在脑微粒体中检测到免疫沉淀物。与纯化的肝脏 HO-1 或脾微粒体 HO-1 的抗原特性不同，脑血红素加氧酶活性与免疫反应性 HO-2 蛋白的量密切相关，并且两者都反映了发育过程中 1.3-kb mRNA 信息的丰度。
Blot hybridization of RNA isolated from rat brain revealed the presence of two HO-2 homologous transcripts (1.3 and 1.9 kilobases (kb] at all stages of development ranging from 1 day before birth to adulthood. The level of both HO-2 messages appeared to be developmentally regulated and a gradual increase was observed from prenatal day 1 to adulthood. The two transcripts were highly homologous as assayed through hybridization studies using probes derived from the 5' end, middle, and 3' end of a cloned rat testis HO-2 cDNA. The 1.3-kb mRNA was essentially identical in size to the testis HO-2 cDNA. The message was efficiently translated in the brain, and is believed to encode the HO-2 protein. It seems unlikely that the 1.9-kb species represents a precursor of the 1.3-kb mRNA, as it was also translated in vivo, although less efficiently than the smaller mRNA species. Neither of the two HO-2 mRNA species were induced by bacterial endotoxin. Unlike HO-2, only one HO-1 transcript of approximately 1.8 kb could be detected. This transcript was of very low abundance and was not developmentally regulated, but could be increased by bacterial endotoxin. The product of this induced message, however, was not detectable by Western immunoblot analysis using antibody raised against liver HO-1. An immunoprecipitate could be detected in brain microsomes by radioimmunoassay using the same antibody. This protein, however, exhibited antigenic properties different from that of the purified liver HO-1 or that of spleen microsomal HO-1. Brain heme oxygenase activity correlated well with the amount of immunoreactive HO-2 protein and both reflect the abundance of the 1.3-kb mRNA message over the course of development.