hCINAP is an atypical mammalian nuclear adenylate kinase with an ATPase motif: structural and functional studies.
hCINAP is an atypical mammalian nuclear adenylate kinase with an ATPase motif: structural and functional studies.
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DOI：
10.1002/prot.23186
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发表时间：
2012-01
影响因子：
2.9
通讯作者：
Zographos, Spyros E.
中科院分区：
文献类型：
--
作者：
Drakou, Christina E.;Malekkou, Anna;Hayes, Joseph M.;Lederer, Carsten W.;Leonidas, Demetres D.;Oikonomakos, Nikos G.;Lamond, Angus I.;Santama, Niovi;Zographos, Spyros E.
人类卷曲蛋白相互作用核ATP酶蛋白（hCINAP）直接与卷曲蛋白（卡哈尔体（CB）的标记蛋白）相互作用，卡哈尔体是参与小核核糖核蛋白UsnRNP和snoRNP成熟的核细胞器。hCINAP以前被指定为腺苷酸激酶（AK 6），但非常不典型，因为它表现出异常广泛的底物特异性、ATP酶/GTP酶蛋白（步行者基序A和B）的结构特征以及固有的ATP酶活性。尽管它的有趣的结构，独特的性能和细胞定位，hCINAP的酶的机制和生物学功能仍然很差的特点。在这里，我们提供了与底物ADP（和dADP）复合的hCINAP的第一个高分辨率结构，在AMP结合位点结合硫酸根离子的hCINAP的结构，以及三元复合物hCINAP-Mg 2 +ADP-Pi的结构。诱导拟合对接计算用于预测hCINAP-Mg ~（2+）ATP-AMP三元复合物的结构。结构分析表明His 79在步行者B基序中起功能作用。动力学分析表明，His 79影响AK和ATP酶的催化效率，并诱导同源二聚体的形成。最后，我们表明，在人体细胞中的hCINAP-H79 G的体内表达是有毒的，并大大失调的细胞核中的CB的数量和外观。我们的研究结果表明，hCINAP可能不仅仅是调节核苷酸稳态，但可能有更广泛的功能，包括控制CB组装和拆卸在人类细胞核。
Human coilin interacting nuclear ATPase protein (hCINAP) directly interacts with coilin, a marker protein of Cajal Bodies (CBs), nuclear organelles involved in the maturation of small nuclear ribonucleoproteins UsnRNPs and snoRNPs. hCINAP has previously been designated as an adenylate kinase (AK6), but is very atypical as it exhibits unusually broad substrate specificity, structural features characteristic of ATPase/GTPase proteins (Walker motifs A and B) and also intrinsic ATPase activity. Despite its intriguing structure, unique properties and cellular localization, the enzymatic mechanism and biological function of hCINAP have remained poorly characterized. Here, we offer the first high-resolution structure of hCINAP in complex with the substrate ADP (and dADP), the structure of hCINAP with a sulfate ion bound at the AMP binding site, and the structure of the ternary complex hCINAP-Mg2+ADP-Pi. Induced fit docking calculations are used to predict the structure of the hCINAP-Mg2+ATP-AMP ternary complex. Structural analysis suggested a functional role for His79 in the Walker B motif. Kinetic analysis of mutant hCINAP-H79G indicates that His79 affects both AK and ATPase catalytic efficiency and induces homodimer formation. Finally, we show that in vivo expression of hCINAP-H79G in human cells is toxic and drastically deregulates the number and appearance of CBs in the cell nucleus. Our findings suggest that hCINAP may not simply regulate nucleotide homeostasis, but may have broader functionality, including control of CB assembly and disassembly in the nucleus of human cells.
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影响因子：
5.6
作者：
Craig, Ian R.;Essex, Jonathan W.;Spiegel, Katrin
通讯作者：
Spiegel, Katrin
影响因子：
5.7
作者：
KJELDGAARD, M;NISSEN, P;NYBORG, J
通讯作者：
NYBORG, J
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD
DOI：
10.1016/s1570-0232(01)00637-7
发表时间：
2002-03-25
影响因子：
3
作者：
Dian, C;Eshaghi, S;Birse, D
通讯作者：
Birse, D