Identification of novel isoforms of human RAD52
Identification of novel isoforms of human RAD52
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DOI：
10.1016/s0167-4781(99)00214-6
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发表时间：
1999-12-23
期刊：
影响因子：
--
通讯作者：
Kamitani, T
中科院分区：
文献类型：
--
作者：
Kito, K;Wada, H;Kamitani, T
在酵母中，RAD 52已被证明是DNA同源重组所必需的，并参与双链DNA断裂的修复。最近，酵母RAD 52的人类同源物，一个418个氨基酸的蛋白质，已被确定。在这项研究中，我们报告了三种不同的亚型的人RAD 52分离脑和睾丸cDNA文库。这些同种型的cDNA含有不同的插入，并由于翻译移码而编码截短的蛋白质。这三种异构体由226-、139-和118-氨基酸残基组成，并分别命名为RAD 52 β、γ和δ。在本文中，原始的RAD 52被称为RAD 52 alpha。这些异构体的信息已在各种人体组织中检测到。我们发现，RAD 52亚型不能与RAD 52 α相互作用，因为自我相互作用结构域的部分缺陷。此外，像RAD 52 α一样，同种型已显示与单链和双链DNA结合。这些结果表明，RAD 52 β、γ和δ可能通过它们的DNA结合特性和它们不能与RAD 52 α结合来影响RAD 52 α功能。因此，这些异构体可能作为显性负突变体或负调节器的RAD 52 α。(C)1999 Elsevier Science B. V.保留所有权利。
In yeast, RAD52 has been shown to be essential for homologous recombination of DNA and to be involved in the repair of double-stranded DNA breaks. Recently, the human homologue of yeast RAD52, a 418-amino-acid protein, has been identified. In this study, we report three different isoforms of human RAD52 isolated from brain and testis cDNA libraries. cDNAs of these isoforms contain distinct insertions and encode truncated proteins due to translational frame-shifts. The three isoforms consist of 226-, 139-, and 118-amino-acid residues, and are designated as RAD52 beta, gamma, and delta, respectively. The original RAD52 is termed as RAD52 alpha in this paper. Messages of these isoforms have been detected in various human tissues. We found that the RAD52 isoforms were unable to interact with RAD52 alpha because of partial defect of the self-interaction domain. Furthermore, like RAD52 alpha, the isoforms have been shown to bind to both single-stranded and double-stranded DNA. These results suggest that RAD52 beta, gamma, and delta might affect RAD52 alpha function through their DNA-binding property and their inability to bind to RAD52 alpha. Thus, these isoforms might act as dominant negative mutants or negative regulators of RAD52 alpha. (C) 1999 Elsevier Science B.V. All rights reserved.