C-terminal Domain of p16INK4a is Adequate in Inducing Cell Cycle Arrest, Growth Inhibition and CDK4/6 Interaction Similar to the Full Length Protein in HT-1080 Fibrosarcoma Cells
C-terminal Domain of p16INK4a is Adequate in Inducing Cell Cycle Arrest, Growth Inhibition and CDK4/6 Interaction Similar to the Full Length Protein in HT-1080 Fibrosarcoma Cells
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DOI：
10.1002/jcb.22892
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发表时间：
2010-12-15
影响因子：
4
通讯作者：
Ghahremani, Mohammad Hossein
中科院分区：
文献类型：
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作者：
Fahham, Najmeh;Sardari, Soroush;Ghahremani, Mohammad Hossein
肿瘤抑制因子p16（INK 4a）作为细胞周期蛋白依赖性激酶（CDKs）4/6的抑制剂被发现后，在肿瘤研究中受到广泛关注。在结构上，它由四个完整的锚蛋白重复序列组成，被认为参与CDK 4相互作用。根据以往关于p16结构域和失活突变的重要性的分歧，我们的目的是寻找具有全长蛋白质功能特性的结构域。在我们的计算机筛选分析，然后进行实验评估，我们已经确定了新的最小功能域的p16的C-末端的一半，包括锚蛋白重复序列III，IV和C-末端侧翼区伴随着环2和3。将这种截短形式转染到缺乏内源性p16的HT-1080人纤维肉瘤细胞中，揭示了它能够抑制细胞生长和增殖，相当于p16（INK 4a）。功能分析表明，该片段与p16一样，可与CDK 4/6相互作用，阻断细胞进入S期，抑制细胞生长。p16最小功能域的鉴定对未来拟肽药物的设计和肿瘤基因转移治疗具有重要意义。J.细胞。111：1598-1606，2010. (C)2010 Wiley-Liss，Inc.
The tumor suppressor p16(INK4a) has earned widespread attention in cancer studies since its discovery as an inhibitor of cyclin-dependent kinases (CDKs) 4/6. Structurally, it consists of four complete ankyrin repeats, believed to be involved in CDK4 interaction. According to the previous disparities concerning the importance of domains and inactivating mutations in p16, we aimed to search for the domain possessing the functional properties of the full length protein. Upon our in silico screening analyses followed by experimental assessments, we have identified the novel minimum functional domain of p16 to be the C-terminal half including ankyrin repeats III, IV and the C-terminal flanking region accompanied by loops 2 and 3. Transfection of this truncated form into HT-1080 human fibrosarcoma cells, lacking endogenous p16, revealed that it is able to inhibit cell growth and proliferation equivalent to p16(INK4a). The functional analysis showed that this fragment like p16 can interact with CDK4/6, block the entry into S phase of the cell cycle and suppress growth as indicated by colony formation assay. Identification of p16 minimum functional domain can be of benefit to the future peptidomimetic drug design as well as gene transfer for cancer therapy. J. Cell. Biochem. 111: 1598-1606, 2010. (C) 2010 Wiley-Liss, Inc.