摘要
蛋白脂蛋白（PLP）基因突变导致Pelizaeus－Merzbacher病（PMD）和部分X-连锁的痉挛性截瘫。Olinsky等克隆了M6b的部分序列（U45955），该基因认为是PLP基因家族成员之一。我们以巢式PCR得到一约300hp的片段，测序为与U45955的5′端局部重叠的新序列，拼接后得到1．642kb的序列，其中含有可编码265个氨基酸的开放阅读框。此阅读框经对脑cDNA文库PCR产物的测序确证（命名为M6ba）。M6ba的CDNA序列及其编码氨基酸序列与小鼠中M6b基因和蛋白质序列显著相似（分别为91．2％和93.4％一致）。Northern杂交的结果及cDNA文库PCR扩增、EST数据库分析的结果提示M6b基因至少存在3种剪接形式。M6ba基因与PLP基因显著相似，并且两蛋白质在所有疏水区高度保守。M6ba基因结构的分析，显示此基因编码区由7个外显子构成。
X-linked, early onset Pelizaeus-Merzbarher disease (PMD) and pat of X-linkedspastic paraplegia are caused by mutation of proteolipid protein. M6b (U45955)partially cloned by Olinsky was considered as a member of PLP gene faxnily- Onenovel fragment about 300bp partially overiapped but differed in 5'part with U45955was obtained by nested PCK Assembly of the novel sequence with U45955 make a1.642kb cDNA sequence with an open reading frame encoding 265 amino acids,which was verified by sequence of PCR products from brain cDNA library. ThecDNA (termed M6ba) and its deduced peptide sequence showed significant similarityto murine M6b gene and protein (91.2% and 93.4% respecitvely). Northern blotamplification in cDNA library and EST analysis indicated that human M6b gene hasat least three splicing forms. M6ba also showed significant similarity to PLP gene,they encode strongly hydrophobic protein and all their hydrophobic region are highlyconserved. Gene structureanalysis showed that the coding region of M6ba wascomposed of seven exons.
基金
SB-湖南医科大学合作研究项目
国家高技术研究发展计划
