Messenger RNAs located in myelin sheath assembly sites
Messenger RNAs located in myelin sheath assembly sites
复制标题
DOI：
10.1046/j.1471-4159.2000.0751834.x
复制
发表时间：
2000-11-01
影响因子：
4.7
通讯作者：
Feinstein, DL
中科院分区：
文献类型：
--
作者：
Gould, RM;Freund, CM;Feinstein, DL
mRNA靶向特定的亚细胞位置被认为有助于其蛋白质产物快速和选择性地掺入可能包括膜细胞器的复合物中。在少突胶质细胞中，编码髓鞘碱性蛋白（MBP）和选择髓鞘相关少突胶质细胞碱性蛋白（MOBP）的mRNA位于髓鞘组装位点（MSAS）。为了鉴定位于MSAS中的其他mRNA，我们使用了亚细胞分级分离和抑制性消减杂交的组合。在分析的1，080个cDNA中，超过50%来自MBP或MOBP mRNA，证实该方法选择了富含MSAS的mRNA。在鉴定的90个其他cDNA中，大多数代表一个或多个富含大鼠脑髓磷脂的mRNA。对编码已知蛋白质的5种cDNA的mRNA大小、髓磷脂富集以及组织和发育表达模式进行了表征。其中两个，肽基精氨酸脱亚氨酶和铁蛋白重链，在髓鞘形成中具有公认的作用。相应的mRNA的大小与先前鉴定的mRNA不同，并且它们具有与MBP mRNA难以区分的组织和发育表达模式。其他三种cDNA识别其蛋白质（SH3p13、KIF1A和动力蛋白轻中间链）参与膜生物发生的mRNA。虽然富含髓鞘，这些mRNA的组织和发育分布模式不同的MBP mRNA。还检查了与已知mRNA不具有显著序列同源性的6个其他cDNA。相应的mRNA在髓鞘中高度富集，并且4个具有与MBP mRNA的组织和发育分布模式无法区分的分布模式。这些研究表明，MSAS含有不同的mRNA群体，其局部合成的蛋白质被放置以促进髓鞘组装和维护。这些mRNA和蛋白质的表征将有助于提供髓鞘组装的全面图片。
The targeting of mRNAs to specific subcellular locations is believed to facilitate the rapid and selective incorporation of their protein products into complexes that may include membrane organelles. In oligodendrocytes, mRNAs that encode myelin basic protein (MBP) and select myelin-associated oligodendrocytic basic proteins (MOBPs) locate in myelin sheath assembly sites (MSAS). To identify additional mRNAs located in MSAS, we used a combination of subcellular fractionation and suppression subtractive hybridization. More than 50% of the 1,080 cDNAs that were analyzed were derived from MBP or MOBP mRNAs, confirming that the method selected mRNAs enriched in MSAS. Of 90 other cDNAs identified, most represent one or more mRNAs enriched in rat brain myelin. Five cDNAs, which encode known proteins, were characterized for mRNA size(s), enrichment in myelin, and tissue and developmental expression patterns. Two of these, peptidylarginine deiminase and ferritin heavy chain, have recognized roles in myelination. The corresponding mRNAs were of different sizes than the previously identified mRNA, and they had tissue and development expression patterns that were indistinguishable from those of MBP mRNA. Three other cDNAs recognize mRNAs whose proteins (SH3p13, KIF1A, and dynein light intermediate chain) are involved in membrane biogenesis. Although enriched in myelin, the tissue and developmental distribution patterns of these mRNAs differed from those of MBP mRNA. Six other cDNAs, which did not share significant sequence homology to known mRNAs, were also examined. The corresponding mRNAs were highly enriched in myelin, and four had tissue and developmental distribution patterns indistinguishable from those of MBP mRNA. These studies demonstrate that MSAS contain a diverse population of mRNAs, whose locally synthesized proteins are placed to contribute to myelin sheath assembly and maintenance. Characterization of these mRNAs and proteins will help provide a comprehensive picture of myelin sheath assembly.