Identification of a novel, highly variable amino-terminal amino acid sequence element in the nuclear intermediate filament protein lamin B2 from higher vertebrates
Identification of a novel, highly variable amino-terminal amino acid sequence element in the nuclear intermediate filament protein lamin B2 from higher vertebrates
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DOI：
10.1016/j.febslet.2006.10.023
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发表时间：
2006-11-13
期刊：
影响因子：
3.5
通讯作者：
Herrmann, Harald
中科院分区：
文献类型：
--
作者：
Schumacher, Jens;Relchenzeller, Michaela;Herrmann, Harald
通过将新获得的人类中间丝蛋白lamin B-2的cDNA序列与已发表的序列进行比较，我们发现在先前假设的翻译起始上游增加了一个60个核苷酸的翻译起始密码子。此外，在黑猩猩、小鼠、大鼠和牛的基因和cDNA中分别鉴定了相应的序列。因此，我们产生了针对这20个潜在的人类序列新氨基酸的抗体。通过免疫印迹分析和免疫荧光显微镜，我们发现人层粘连蛋白B2确实合成了一个比以前报道的更长的版本，因为它含有这20个额外的氨基酸。值得注意的是，在这一片段中，与小鼠、大鼠和牛层粘连蛋白B2的序列同源性显著低于第二个蛋氨酸密码子和α-螺旋杆开始之间的序列同源性，这表明“头”的顶端参与了更多物种特有的功能。在人培养的SW-13细胞中强制表达GFP标记的真核“长”和20个氨基酸的短版本lamin B2表明，长版本和短版本都正确地整合到核层中，尽管短版本在高表达水平时表现出扰乱包膜结构的倾向。(C)2006年欧洲生化学会联合会。爱思唯尔出版，版权所有。
By comparing newly available cDNA sequences of the human intermediate filament protein lamin B-2 with published sequences, we have identified an additional translation initiation codon 60 nucleotides upstream of the previously assumed translation start. In addition, corresponding sequences were identified in the chimpanzee, mouse, rat and bovine genes and cDNAs, respectively. Therefore, we generated antibodies against these potential 20 new amino acids of the human sequence. By immunoblot analysis and immunofluorescence microscopy we show that human lamin B2 is indeed synthesized as a longer version than previously reported, because it contains these additional 20 amino acids. Notably, the sequence homology to mouse, rat and bovine lamin B2 is significantly lower in this segment than in that between the second methionine codon and the start of the alpha-helical rod indicating that the tip of the "head" is engaged in more species-specific functions. Forced expression of the GFP-tagged authentic "long" and the 20 amino acid shorter version of lamin B2 in human cultured SW-13 cells demonstrated that both the longer and the shorter version are properly integrated into the nuclear lamina, although the shorter version exhibited a tendency to disturb envelope architecture at higher expression levels. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.