Reduction of meckelin leads to general loss of cilia, ciliary microtubule misalignment and distorted cell surface organization.
Reduction of meckelin leads to general loss of cilia, ciliary microtubule misalignment and distorted cell surface organization.
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DOI：
10.1186/2046-2530-3-2
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发表时间：
2014-01-31
期刊：
影响因子：
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通讯作者：
Van Houten J
中科院分区：
文献类型：
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作者：
Picariello T;Valentine MS;Yano J;Van Houten J
Meckelin （MKS3）是一种与Meckel综合征相关的保守蛋白，它有助于中心粒向细胞表面迁移，从而促进纤毛形成。我们利用RNA干扰（RNAi）和FLAG表位标记蛋白的表达在纤毛原生动物四甲草草虫中探索了MKS3p的其他功能。这种细胞具有高度组织化的细胞表面，有数以千计的纤毛和基体，它们被分成一个或两个基体单位，由脊划分。四毛虫细胞表面的高度系统化为MKS和其他纤毛病提供了一种研究模型，可以很容易地观察到纤毛结构、亚细胞组织和细胞表面整体排列的变化。我们使用IFT88中减少的细胞进行比较，因为该基因产物与纤毛维持和生长的关系已被很好地理解。FLAG-MKS3p出现在过渡区远端基底平面上方。大约95%的观察到的基底体有FLAG-MKS3染色。MKS3缺失细胞的RNAi表型包括整体缩短和纤毛丢失。基底体结构未受影响。在背表面，基生体及其相关的小根从正常的前后排列中旋转出一条直线。同样，皮质单元形状异常，与正常排列不对齐。使用MKS3线圈-线圈域的GST下拉表明以前未识别的相互作用伙伴。MKS3p的减少表明该蛋白影响整个细胞表面纤毛的发育和维持。MKS3p的复位在背表面最为明显。前基体附着并沿后基体的条纹根移动，为复制做准备。我们认为，随着MKS3p的减少，基底体的这种附着和引导失去了。基底体偏离航向，导致基底体行不对齐和单位畸形。小根通常在这些不对齐的基体上形成，但被旋转出其正确的方向。我们的假设得到了MKS3p新的相互作用伙伴的进一步支持，包括着丝细胞纤维蛋白KdB2。
Meckelin (MKS3), a conserved protein linked to Meckel Syndrome, assists in the migration of centrioles to the cell surface for ciliogenesis. We explored for additional functions of MKS3p using RNA interference (RNAi) and expression of FLAG epitope tagged protein in the ciliated protozoan Paramecium tetraurelia. This cell has a highly organized cell surface with thousands of cilia and basal bodies that are grouped into one or two basal body units delineated by ridges. The highly systematized nature of the P. tetraurelia cell surface provides a research model of MKS and other ciliopathies where changes in ciliary structure, subcellular organization and overall arrangement of the cell surface can be easily observed. We used cells reduced in IFT88 for comparison, as the involvement of this gene’s product with cilia maintenance and growth is well understood. FLAG-MKS3p was found above the plane of the distal basal body in the transition zone. Approximately 95% of those basal bodies observed had staining for FLAG-MKS3. The RNAi phenotype for MKS3 depleted cells included global shortening and loss of cilia. Basal body structure appeared unaffected. On the dorsal surface, the basal bodies and their associated rootlets appeared rotated out of alignment from the normal anterior-posterior rows. Likewise, cortical units were abnormal in shape and out of alignment from normal rows. A GST pull down using the MKS3 coiled-coil domain suggests previously unidentified interacting partners. Reduction of MKS3p shows that this protein affects development and maintenance of cilia over the entire cell surface. Reduction of MKS3p is most visible on the dorsal surface. The anterior basal body is attached to and moves along the striated rootlet of the posterior basal body in preparation for duplication. We propose that with reduced MKS3p, this attachment and guidance of the basal body is lost. The basal body veers off course, causing basal body rows to be misaligned and units to be misshapen. Rootlets form normally on these misaligned basal bodies but are rotated out of their correct orientation. Our hypothesis is further supported by the identification of novel interacting partners of MKS3p including a kinetodesmal fiber protein, KdB2.