IDENTIFICATION OF DOMAINS OF POLY(ADP-RIBOSE) POLYMERASE FOR PROTEIN-BINDING AND SELF-ASSOCIATION
IDENTIFICATION OF DOMAINS OF POLY(ADP-RIBOSE) POLYMERASE FOR PROTEIN-BINDING AND SELF-ASSOCIATION
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DOI：
10.1074/jbc.270.7.3370
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发表时间：
1995-02-17
影响因子：
4.8
通讯作者：
KUN, E
中科院分区：
文献类型：
--
作者：
BUKI, KG;BAUER, PI;KUN, E
从正常细胞和癌细胞中提取的细胞蛋白质在硝酸纤维素膜transblots上结合聚合ADP-核糖转移酶（pADPRT）。1 mg/ml浓度的组蛋白完全阻止pADPRT与细胞蛋白的结合，表明组蛋白与pADPRT位点的结合竞争性阻断了pADPRT与除组蛋白以外的蛋白的结合。pADPRT与组蛋白的直接结合通过与戊二醛的交联来显示。COOH末端碱性组蛋白H1尾与pADPRT的碱性多肽结构域结合。存在于核心组蛋白的NH 2-末端部分的基本结构域是所有核心组蛋白的可能共同的结构特征，其解释了它们与pADPRT的结合。通过CNBr片段鉴定了pADPRT的两个多肽结构域，以结合组蛋白。这两个结构域位于pADPRT的64-kDa片段内，并且与显示参与pADPRT的自缔合的多肽结构域相邻，终止于第606个氨基酸残基。因此，参与DNA结合的pADPRT多肽结构域也显示与其它蛋白质缔合。完整的pADPRT结合pADPRT的无锌或锌重构的碱性多肽片段。组蛋白通过增加pADPRT上短寡聚体的数量来激活pADPRT的自动聚（ADP）核糖基化。该反应也以双相方式依赖于pADPRT的浓度。溶液中的组蛋白仅少量聚（ADP）-核糖基化，但当掺入人工核小体结构中时是良好的聚合物受体。
Cellular proteins extracted from normal and cancer cells bind polymerizing ADP-ribose transferase (pADPRT) on nitrocellulose membrane transblots. Histones at 1 mg/ml concentration completely prevent the binding of pADPRT to cellular proteins, indicating that the binding of histones to pADPRT sites competitively blocks the association of pADPRT to proteins other than histones. The direct binding of pADPRT to histones is shown by cross-linking with glutaraldehyde. The COOH-terminal basic histone H1 tail binds to the basic polypeptide domain of pADPRT. The basic domain present in the NH2-terminal part of core histones is the probable common structural feature of all core histones that accounts for their binding to pADPRT. Two polypeptide domains of pADPRT were identified, by way of CNBr fragments, to bind histones. These two domains are located within the 64-kDa fragment of pADPRT and are contiguous with the polypeptide domains that were shown to participate in self-association of pADPRT, ending at the 606th amino acid residue. The polypeptide domains of pADPRT which participate in DNA binding are thus shown to associate also with other proteins. Intact pADPRT binds to both the zinc-free or zinc-reconstituted basic polypeptide fragments of pADPRT. Histones activate auto-poly(ADP)-ribosylation of pADPRT by increasing the number of short oligomers on pADPRT. This reaction is also dependent in a biphasic manner on the concentration of pADPRT. Histones in solution are only marginally poly(ADP)-ribosylated but are good polymer accepters when incorporated into artificial nucleosome structures.