A repeated element in the human lamin B2 gene covers most of an intron and reiterates the exon/intron junction
A repeated element in the human lamin B2 gene covers most of an intron and reiterates the exon/intron junction
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DOI：
10.1016/s0378-1119(97)00239-4
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发表时间：
1997-09-01
期刊：
影响因子：
3.5
通讯作者：
Biamonti, G
中科院分区：
文献类型：
--
作者：
deStanchina, E;Perini, G;Biamonti, G
核纤层蛋白是中间丝型蛋白质，形成位于内核膜下方的纤维状网状结构。我们之前报道过人类核纤层蛋白 B2 基因的鉴定，该基因映射到 19 号染色体的亚端粒带 p13.3，非常接近人类 DNA 复制起点。在这里，我们报告了在人类核纤层蛋白 B2 基因中鉴定出一种新的重复元件（可变数量的串联重复序列：VNTR），该元件似乎起源于最近，但在小鼠和灵长类动物（如鹿猴、狐猴和猕猴）的基因组中不存在。 VNTR 与核纤层蛋白 B2 基因的外显子 8 相邻，尽管该基因编码蛋白质的核定位信号，但在氨基酸和核苷酸水平上在物种之间存在高度差异。此外，以约100bp的重复单元为特征的VNTR覆盖了基因的大部分内含子8，并且重复了上游外显子的最后7bp和外显子/内含子连接处。对 HeLa 细胞 RNA 进行的 RT-PCR 实验表明，在核纤层蛋白 B2 前体 mRNA 的加工过程中没有使用任何下游连接。 (C) 1997 Elsevier Science B.V.
Nuclear lamins are intermediate filament-type proteins forming a fibrillar meshwork that underlies the inner nuclear membrane. We have previously reported the identification of the human lamin B2 gene that maps to the subtelomeric band p13.3 of chromosome 19 in close proximity of a human DNA replication origin. Here we report the identification within the human lamin B2 gene of a novel repeated element (variable number of tandem repeats: VNTR) that appears to have a very recent origin, being absent in the genome of mouse and primates such as cercopitheques, lemurs and macaques. The VNTR is adjacent to exon 8 of the lamin B2 gene which, albeit encoding the nuclear localization signal of the protein, is highly divergent both at amino acid and nucleotide level among species. Moreover the VNTR, characterized by a repeated unit of about 100 bp, covers most of intron 8 of the gene and reiterates both the last 7 bp of the upstream exon and the exon!intron junction. RT-PCR experiments carried out on HeLa cell RNA suggest that none of the downstream junctions is used during the processing of the lamin B2 pre-mRNA. (C) 1997 Elsevier Science B.V.