Two forms of the apoptosis-linked protein ALG-2 with different Ca2+ affinities and target recognition
Two forms of the apoptosis-linked protein ALG-2 with different Ca2+ affinities and target recognition
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DOI：
10.1074/jbc.275.14.10514
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发表时间：
2000-04-07
影响因子：
4.8
通讯作者：
Berchtold, MW
中科院分区：
文献类型：
--
作者：
Tarabykina, S;Moller, AL;Berchtold, MW
ALG-2基因是一个与钙离子结合的五肽EF-hand家族蛋白。为了研究ALG-2重组蛋白的钙离子结合特性，我们从小鼠肝脏mRNA中克隆了ALG-2 cDNA。序列分析表明，存在两种类型的克隆。一种（命名为ALG-2，5）对应于公开的ALG-2序列（Vito，P.，Lacana，E.，和D 'Adamio，L.（1996）Science 271，521-525）;第二种（命名为ALG-2，1）短6个核苷酸，并且相应的蛋白质缺少氨基酸残基Gly（121）和Phe（122）。两种转录物以相同的2：1摩尔比存在于小鼠组织中。ALG-2，5和ALG-2，1重组蛋白质以无金属形式完全可溶，但是可以通过Ca 2+从细菌裂解物中沉淀。在TR een的存在下，Ca 2+结合曲线显示两个高亲和力位点，ALG-2，5和ALG-2，1的[Ca 2 +]（0.5）值分别为1.2和3.1 μ M，加上一个低亲和力位点。使用酵母双杂交系统，我们表明，这两种蛋白质有很强的倾向，形成同源和异源二聚体。与ALG-2，5相反，ALG-2，1同种型不与靶蛋白AIP-1相互作用，该靶蛋白AIP-1早先被描述为在细胞凋亡中起作用（Vito，P.，佩莱格里尼湖，Guiet，C.，和D 'Adamio，L.（1999）J.Biol.Chem.274，1533-1540），我们提出ALG-2，5和ALG-2，1之间的微小序列差异影响蛋白质的Ca 2+结合特性和功能。
The apoptosis-linked gene ALG-2 encodes a Ca2+-binding protein of the penta EF-hand family, To investigate the Ca2+ binding properties of the recombinant ALG-2 protein, Re have cloned ALG-2 cDNA from mouse liver mRNA. Sequence analysis showed that two types of clones were present. One (named ALG-2,5) corresponds to the published ALG-2 sequence (Vito, P., Lacana, E., and D'Adamio, L. (1996) Science 271, 521-525); the second (named ALG-2,1) is 6 nucleotides shorter, and the corresponding protein lacks the amino acid residues Gly(121) and Phe(122), Both transcripts are present in mouse tissues in the same 2:1 molar ratio, The ALG-2,5 and ALG-2,1 recombinant proteins are fully soluble in the metal-free form but can be precipitated from bacterial lysates by Ca2+. In the presence of TR een the Ca2+ binding profiles display two high affinity sites with [Ca2+](0.5) values of 1.2 and 3.1 mu M for ALG-2,5 and ALG-2,1, respectively, plus one low affinity site. Using the yeast two-hybrid system we demonstrate that both proteins have a strong tendency to form homo- and heterodimers. In contrast to ALG-2,5, the ALG-2,1 isoform does not interact with the target protein AIP-1, earlier described to play a role in apoptosis (Vito, P., Pellegrini, L., Guiet, C., and D'Adamio, L. (1999) J. Biol, Chem. 274, 1533-1540), We propose that the minor sequence difference between ALG-2,5 and ALG-2,1 affects the Ca2+ binding properties and function of the proteins.