A subclass of plant heat shock cognate 70 chaperones carries a motif that facilitates trafficking through plasmodesmata
A subclass of plant heat shock cognate 70 chaperones carries a motif that facilitates trafficking through plasmodesmata
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DOI：
10.1073/pnas.252427999
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发表时间：
2002-12-10
影响因子：
11.1
通讯作者：
Lucas, WJ
中科院分区：
文献类型：
--
作者：
Aoki, K;Kragler, F;Lucas, WJ
胞间连丝建立了非细胞自主作用蛋白和核糖核蛋白复合物的运输途径。利用细胞质间壁富集的细胞组分和韧皮部汁液形式的去核筛元素的含量，分离和表征与这种细胞间运输途径相关的热休克同源70 （Hsc70）伴侣。我们克隆了三个Cucurbita maxima Hsc70伴侣蛋白，并通过功能和序列分析鉴定了一个以前未被表征的非细胞自主伴侣蛋白亚类。热休克蛋白70 （Hsp70）家族的高度保守性，结合突变分析，允许表征一个基序，使这些Hsc70伴侣参与胞浆间质非细胞自主易位机制。通过对人类Hsp70进行工程改造，获得了通过胞间连丝进行交通的能力，从而证明了该基序对于Hsp70的运动获得功能是必要的。这些结果讨论了Hsc70伴侣蛋白亚类在非细胞自主蛋白运输中可能发挥的作用。
Plasmodesmata establish a pathway for the trafficking of non-cell-autonomously acting proteins and ribonucleoprotein complexes. Plasmodesmal enriched cell fractions and the contents of enucleate sieve elements, in the form of phloem sap, were used to isolate and characterize heat shock cognate 70 (Hsc70) chaperones associated with this cell-to-cell transport pathway. Three Cucurbita maxima Hsc70 chaperones were cloned and functional and sequence analysis led to the identification of a previously uncharacterized subclass of non-cell-autonomous chaperones. The highly conserved nature of the heat shock protein 70 (Hsp70) family, in conjunction with mutant analysis, permitted the characterization of a motif that allows these Hsc70 chaperones to engage the plasmodesmal non-cell-autonomous translocation machinery. Proof of concept that this motif is necessary for Hsp70 gain-of-movement function was obtained through the engineering of a human Hsp70 that acquired the capacity to traffic through plasmodesmata. These results are discussed in terms of the roles likely played by this subclass of Hsc70 chaperones in the trafficking of non-cell-autonomous proteins.