Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia.
Pirogov Russian National Research Medical University, Moscow, 117997, Russia.
Cell Tissue Res. 2018 Apr;372(1):33-40. doi: 10.1007/s00441-017-2762-1. Epub 2018 Jan 2.
Sphingomyelin synthase genes (Sgms1 and Sgms2) encode the vital enzymes that participate in the processes of membrane transport, cell proliferation and apoptosis. We previously determined the exon-intron structure of Sgms1 and some features of its expression in human and rodent tissues. The circular RNAs (circRNAs) emerging from exons of the 5'-untranslated region (5'-UTR) of Sgms1 were determined. These circRNAs are represented at a high level in the adult brain. Here, we demonstrate that, in contrast to Sgms1, Sgms2 does not contain the multi-exon 5'-UTR but encodes circRNAs, which are composed of the coding region of the gene and are expressed at a low level. We present a study of the expression of sphingomyelin synthase genes in rat brain at embryonic days 7, 9, 13, 17 and 21 and in adult rat brain. In contrast to Sgms1, Sgms2 is expressed at a significantly low level in adult brain. In embryonic rat brain, the mRNA expression of sphingomyelin synthase genes is varied in a developmental stage-specific manner. The level of Sgms1 mRNAs, differing by 5'-UTR-in the formation of which alternative promoters can participate-changes significantly during the process of embryonic development. The expression of circRNAs of Sgms1 was significantly raised during rat embryonic brain development. We assume that the circRNAs are involved in the regulation of sphingomyelin synthase activity in rat brain in different developmental stages.
鞘磷脂合酶基因（Sgms1 和 Sgms2）编码参与膜转运、细胞增殖和凋亡过程的重要酶。我们之前确定了 Sgms1 的外显子-内含子结构及其在人和啮齿动物组织中的表达特征。确定了来自 Sgms1 5'-非翻译区（5'-UTR）外显子的环状 RNA（circRNA）。这些 circRNA 在成年大脑中高水平表达。在这里，我们证明与 Sgms1 相反，Sgms2 不包含多外显子 5'-UTR，但编码 circRNA，由基因的编码区组成，表达水平较低。我们研究了大鼠胚胎期 7、9、13、17 和 21 天和成年大鼠大脑中鞘磷脂合酶基因的表达。与 Sgms1 相反，Sgms2 在成年大脑中的表达水平显著较低。在胚胎大鼠大脑中，鞘磷脂合酶基因的 mRNA 表达以发育阶段特异性的方式变化。Sgms1 mRNAs 的水平差异很大，其 5'-UTR 的形成可能涉及不同的启动子参与-在胚胎发育过程中发生显著变化。Sgms1 的 circRNA 表达在大鼠胚胎脑发育过程中显著升高。我们假设 circRNA 参与不同发育阶段大鼠大脑中鞘磷脂合酶活性的调节。
