Myosin Vb is associated with plasma membrane recycling systems
Myosin Vb is associated with plasma membrane recycling systems
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DOI：
10.1091/mbc.12.6.1843
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发表时间：
2001-06-01
影响因子：
3.3
通讯作者：
Goldenring, JR
中科院分区：
文献类型：
--
作者：
Lapierre, LA;Kumar, R;Goldenring, JR
肌球蛋白Va与许多细胞类型中的离散囊泡群体相关，但对肌球蛋白Vb的功能知之甚少。酵母双杂交筛选的兔壁细胞cDNA文库显性活性Rab 11 a（Rab 11 aS 20 V）确定肌球蛋白Vb作为Rab 11 a，质膜再循环系统的标志物的相互作用蛋白。分离的克隆，对应于肌球蛋白Vb尾部的羧基末端60 kDa，与Rab 11家族的所有成员（Rab 11 a，Rab 11b和Rab 25）相互作用。GFP-肌球蛋白Vb和内源性肌球蛋白Vb与Rab 11 a在HeLa和Madin-Darby犬肾（MDCK）细胞中共分布。与Rab 11 a在MDCK细胞中一样，肌球蛋白Vb免疫反应性在诺考达唑处理后分散，并在紫杉醇处理后重新定位到细胞的顶角。一个绿色荧光蛋白（GFP）-肌球蛋白Vb尾部嵌合体在HeLa细胞中过表达，延缓转铁蛋白的回收，并导致转铁蛋白和转铁蛋白受体的积累在pericentrosomal囊泡。稳定表达多聚伊加受体的极化MDCK细胞中的肌球蛋白Vb尾嵌合体的表达引起基底外侧内吞的多聚伊加和多聚伊加受体在粒体周围区域的积累。肌球蛋白Vb尾对极化MDCK细胞中转铁蛋白的运输没有影响。GFP-肌球蛋白Va尾不与Rab 11 a共定位，并且对HeLa或MDCK细胞中的再循环系统囊泡分布没有影响。结果表明，肌球蛋白Vb与非极化细胞的质膜循环系统和极化细胞的顶端循环系统有关。肌球蛋白Vb尾部嵌合体的显性负效应表明，这种非常规的肌球蛋白是需要运输出质膜再循环系统。
Myosin Va is associated with discrete vesicle populations in a number of cell types, but little is known of the function of myosin Vb. Yeast two-hybrid screening of a rabbit parietal cell cDNA library with dominant active Rab11a (Rab11aS20V) identified myosin Vb as an interacting protein for Rab11a, a marker for plasma membrane recycling systems. The isolated clone, corresponding to the carboxyl terminal 60 kDa of the myosin Vb tail, interacted with all members of the Rab11 family (Rab11a, Rab11b, and Rab25). GFP-myosin Vb and endogenous myosin Vb immunoreactivity codistributed with Rab11a in HeLa and Madin-Darby canine kidney (MDCK) cells. As with Rab11a in MDCK cells, the myosin Vb immunoreactivity was dispersed with nocodazole treatment and relocated to the apical corners of cells with taxol treatment. A green fluorescent protein (GFP)-myosin Vb tail chimera overexpressed in HeLa cells retarded transferrin recycling and caused accumulation of transferrin and the transferrin receptor in pericentrosomal vesicles. Expression of the myosin Vb tail chimera in polarized MDCK cells stably expressing the polymeric IgA receptor caused accumulation of basolaterally endocytosed polymeric IgA and the polymeric IgA receptor in the pericentrosomal region. The myosin Vb tail had no effects on transferrin trafficking in polarized MDCK cells. The GFP-myosin Va tail did not colocalize with Rab11a and had no effects on recycling system vesicle distribution in either HeLa or MDCK cells. The results indicate myosin Vb is associated with the plasma membrane recycling system in nonpolarized cells and the apical recycling system in polarized cells. The dominant negative effects of the myosin Vb tail chimera indicate that this unconventional myosin is required for transit out of plasma membrane recycling systems.