PtdIns-specific MPR pathway association of a novel WD40 repeat protein, WIPI49
PtdIns-specific MPR pathway association of a novel WD40 repeat protein, WIPI49
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DOI：
10.1091/mbc.e03-10-0732
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发表时间：
2004-06-01
影响因子：
3.3
通讯作者：
Parker, PJ
中科院分区：
文献类型：
--
作者：
Jeffries, TR;Dove, SK;Parker, PJ
WIPI 49是一个以前未描述的WD 40重复蛋白家族的成员，我们证明结合3-磷酸化磷酸肌醇。免疫荧光成像表明，WIPI 49是本地化的trans-Golgi和内体膜，细胞器之间的交通在微管依赖的方式。活细胞成像确定WIPI 49穿过与甘露糖-6-磷酸受体（MPR）相同的一组内体膜，并且与此一致，WIPI 49富集在网格蛋白包被的囊泡中。野生型WIPI 49的异位表达破坏了该MPR途径的正常功能，而不能结合磷酸肌醇的双点突变体（R221，222 AWIP 149）的表达不破坏该途径。最后，通过RNAi抑制WIP 149的表达，证明其存在是CI-MPR的正常内体组织和分布所必需的。我们的结论是，WIPI 49是一种新的内体和MPR通路的调节成分，这种作用是依赖于其WD 40域的PI结合特性。
WIPI49 is a member of a previously undescribed family of WD40-repeat proteins that we demonstrate binds 3-phosphorylated phosphoinositides. Immunofluorescent imaging indicates that WIPI49 is localized to both trans-Golgi and endosomal membranes, organelles between which it traffics in a microtubule-dependent manner. Live cell imaging establishes that WIPI49 traffics through the same set of endosomal membranes as that followed by the mannose-6-phosphate receptor (MPR), and consistent with this, WIPI49 is enriched in clathrin-coated vesicles. Ectopic expression of wild-type WIPI49 disrupts the proper functioning of this MPR pathway, whereas expression of a double point mutant (R221,222AWIP149) unable to bind phosphoinositides does not disrupt this pathway. Finally, suppression of WIP149 expression through RNAi, demonstrates that its presence is required for normal endosomal organization and distribution of the CI-MPR. We conclude that WIPI49 is a novel regulatory component of the endosomal and MPR pathway and that this role is dependent upon the PI-binding properties of its WD40 domain.