Identification of protein p270/Tpr as a constitutive component of the nuclear pore complex-attached intranuclear filaments.
Identification of protein p270/Tpr as a constitutive component of the nuclear pore complex-attached intranuclear filaments.
复制标题
将蛋白质p270/TPR鉴定为核孔复合体核内细丝的组成部分。
DOI：
10.1083/jcb.136.3.515
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发表时间：
1997-02-10
期刊：
影响因子：
--
通讯作者：
Franke WW
中科院分区：
文献类型：
--
作者：
Cordes VC;Reidenbach S;Rackwitz HR;Franke WW
利用单抗mAb203-37，我们鉴定了一种多肽：MR-∼270kD(P270)，它是多种脊椎动物细胞核孔复合体核质环上核内细丝的一般成分。利用cDNA克隆和免疫生物化学方法，我们发现人类P270蛋白的预测分子质量为267kD，与其他人报道的位于NPC(Byrd，D.A.，D.J.Sweet，N.Pante，K.N.Konstantinov，T.Guan，A.C.S.Sapire，P.J.Mitchell，C.S.Cooper，U.Aebi和L.Gerace)胞质表面的卷曲卷曲主导蛋白Tpr基本相同。1994年。J.细胞生物学。127：1515-1526)。为了阐明这一有争议的定位，我们在不同种类的哺乳动物和两栖动物细胞中进行了免疫电子显微镜观察，并针对人和非洲爪哇P270/Tpr的不同表位产生了一系列抗体。在这些实验中，蛋白质一直和唯一地在NPC附着的核内细丝中被检测到，并且含有p270/Tpr的细丝束已经被追踪到核内部长达350 nm。未观察到任何p270/Tpr抗体与鼻咽癌细胞质侧的反应，而对照抗体，如针对RanBP2/Nup358蛋白的抗体，则特异性装饰鼻咽癌细胞的细胞质环。各种哺乳动物和两栖类细胞的胞质环状片层的孔复合体也缺乏免疫可检测的蛋白p270/Tpr。我们得出结论，这种卷曲卷曲蛋白是核内NPC连接细丝中普遍存在的成分，并讨论了其可能的功能。
Using a monoclonal antibody, mAb 203-37, we have identified a polypeptide of M r ∼270 kD (p270) as a general constituent of the intranuclear filaments attached to the nucleoplasmic annulus of the nuclear pore complex (NPC) in diverse kinds of vertebrate cells. Using cDNA cloning and immunobiochemistry, we show that human protein p270 has a predicted molecular mass of 267 kD and is essentially identical to the coiled-coil dominated protein Tpr reported by others to be located on the outer, i.e., cytoplasmic surface of NPCs (Byrd, D.A., D.J. Sweet, N. Pante, K.N. Konstantinov, T. Guan, A.C.S. Saphire, P.J. Mitchell, C.S. Cooper, U. Aebi, and L. Gerace. 1994. J. Cell Biol. 127: 1515–1526). To clarify this controversial localization, we have performed immunoelectron microscopy in diverse kinds of mammalian and amphibian cells with a series of antibodies raised against different epitopes of human and Xenopus laevis p270/Tpr. In these experiments, the protein has been consistently and exclusively detected in the NPC-attached intranuclear filaments, and p270/Tpr-containing filament bundles have been traced into the nuclear interior for up to 350 nm. No reaction has been noted at the cytoplasmic side of NPCs with any of the p270/Tpr antibodies, whereas control antibodies such as those against protein RanBP2/ Nup358 specifically decorate the cytoplasmic annulus of NPCs. Pore complexes of cytoplasmic annulate lamellae in various mammalian and amphibian cells are also devoid of immunodetectable protein p270/Tpr. We conclude that this coiled-coil protein is a general and ubiquitous component of the intranuclear NPC- attached filaments and discuss its possible functions.