AtATG genes, homologs of yeast autophagy genes, are involved in constitutive autophagy in Arabidopsis root tip cells
AtATG genes, homologs of yeast autophagy genes, are involved in constitutive autophagy in Arabidopsis root tip cells
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DOI：
10.1093/pcp/pcl031
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发表时间：
2006-12-01
影响因子：
4.9
通讯作者：
Moriyasu, Yuji
中科院分区：
文献类型：
--
作者：
Inoue, Yuko;Suzuki, Takao;Moriyasu, Yuji
在含有足够营养和膜透性蛋白酶抑制剂E-64 d的培养基中培养的拟南芥根尖中，从分生区到伸长区，部分细胞质积累在细胞的液泡中。在E-64处理的大麦根尖中，部分细胞质积累在自溶体和预先存在的中央液泡中。这些结果表明，空泡和/或溶酶体自噬发生在这些区域的细胞组成。自噬抑制剂3-甲基腺嘌呤可抑制拟南芥根尖细胞中此类内含物的积累。在从拟南芥T-DNA突变体制备的根尖中也没有观察到这样的内含物，其中AtATG 2或AtATG 5（自噬所必需的酵母ATG基因的拟南芥同源物）被破坏。与此相反，atatg 9突变体，其中另一个同源的ATG被破坏，积累了大量的空泡包涵体的存在下，E-64 d。这些结果表明，AtAtg 2和AtAtg 5蛋白是必不可少的自噬，而AtAtg 9蛋白有助于，但不是必不可少的，在拟南芥根尖细胞的自噬。自噬对3-甲基腺嘌呤敏感并依赖于Atg蛋白，组成性地发生在拟南芥的根尖细胞中。
In Arabidopsis root tips cultured in medium containing sufficient nutrients and the membrane-permeable protease inhibitor E-64d, parts of the cytoplasm accumulated in the vacuoles of the cells from the meristematic zone to the elongation zone. Also in barley root tips treated with E-64, parts of the cytoplasm accumulated in autolysosomes and preexisting central vacuoles. These results suggest that vacuolar and/or lysosomal autophagy occurs constitutively in these regions of cells. 3-Methyladenine, an inhibitor of autophagy, inhibited the accumulation of such inclusions in Arabidopsis root tip cells. Such inclusions were also not observed in root tips prepared from Arabidopsis T-DNA mutants in which AtATG2 or AtATG5, an Arabidopsis homolog of yeast ATG genes essential for autophagy, is disrupted. In contrast, an atatg9 mutant, in which another homolog of ATG is disrupted, accumulated a significant number of vacuolar inclusions in the presence of E-64d. These results suggest that both AtAtg2 and AtAtg5 proteins are essential for autophagy whereas AtAtg9 protein contributes to, but is not essential for, autophagy in Arabidopsis root tip cells. Autophagy that is sensitive to 3-methyladenine and dependent on Atg proteins constitutively occurs in the root tip cells of Arabidopsis.