M-phase-specific phosphorylation and structural rearrangement of the cytoplasmic cross-linking protein plectin involve p34(cdc2) kinase
M-phase-specific phosphorylation and structural rearrangement of the cytoplasmic cross-linking protein plectin involve p34(cdc2) kinase
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DOI：
10.1091/mbc.7.2.273
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发表时间：
1996-02-01
影响因子：
3.3
通讯作者：
Wiche, G
中科院分区：
文献类型：
--
作者：
Foisner, R;Malecz, N;Wiche, G
凝集素是一种广泛存在的、丰富的细胞骨架交联蛋白，在整个细胞周期中作为蛋白激酶的靶点，在总体磷酸化水平上没有任何显著变化。在有丝分裂过程中，发现该分子的各种磷酸化位点之一优先被磷酸化。通过在稳定转染的中国仓鼠卵巢细胞中异位表达的凝集素结构域的体内磷酸化，该位点被映射到多肽的C-末端重复序列6结构域。相同的位点已被鉴定为p34（cdc 2）激酶的体外靶点。有丝分裂特异性磷酸化的plectin是伴随着一个重组的plectin结构，改变从一个丝状的，主要是波形蛋白相关的状态在间期的扩散波形蛋白独立的分布在有丝分裂中可视化的免疫荧光显微镜。亚细胞分级分离研究表明，在间期细胞中，高达80%的细胞网蛋白与主要由中间丝组成的不溶性细胞部分相关，而在有丝分裂期间，大多数网蛋白（> 75%）变得可溶。此外，p34（cdc 2）激酶磷酸化纯化的plectin降低plectin的能力，在体外预组装的波形蛋白丝相互作用。总之，我们的数据表明，有丝分裂特异性磷酸化涉及p34（cdc 2）激酶调节细胞周期中的纤维素的交联活动和协会与中间丝。
Plectin, a widespread and abundant cytoskeletal cross-linking protein, serves as a target for protein kinases throughout the cell cycle, without any significant variation in overall phosphorylation level. One of the various phosphorylation sites of the molecule was found to be phosphorylated preferentially during mitosis. By in vivo phosphorylation of ectopically expressed plectin domains in stably transfected Chinese hamster ovary cells, this site was mapped to the C-terminal repeat 6 domain of the polypeptide. The same site has been identified as an in vitro target for p34(cdc2) kinase. Mitosis-specific phosphorylation of plectin was accompanied by a rearrangement of plectin structures, changing from a filamentous, largely vimentin-associated state in interphase to a diffuse vimentin-independent distribution in mitosis as visualized by immunofluorescence microscopy. Subcellular fractionation studies showed that in interphase cells up to 80% of cellular plectin was found associated with an insoluble cell fraction mostly consisting of intermediate filaments, while during mitosis the majority of plectin (> 75%) became soluble. Furthermore, phosphorylation of purified plectin by p34(cdc2) kinase decreased plectin's ability to interact with preassembled vimentin filaments in vitro. Together, our data suggest that a mitosis-specific phosphorylation involving p34(cdc2) kinase regulates plectin's cross-linking activities and association with intermediate filaments during the cell cycle.