Nucleic acid uptake occurs independent of lysosomal acidification but dependent on ATP consumption during RNautophagy/DNautophagy
Nucleic acid uptake occurs independent of lysosomal acidification but dependent on ATP consumption during RNautophagy/DNautophagy
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DOI：
10.1016/j.bbrc.2022.12.090
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发表时间：
2023-01-12
影响因子：
3.1
通讯作者：
Kabuta，Tomohiro
中科院分区：
文献类型：
--
作者：
Contu，Viorica Raluca;Sakai，Ryohei;Kabuta，Tomohiro
RN自噬/DN自噬（RDA）是一种自噬过程，是指溶酶体直接摄取核酸并进行降解。自噬依赖于溶酶体，溶酶体酸化对于细胞内成分的降解至关重要。然而，溶酶体酸化是否会干扰 RDA 期间的核酸摄取尚不清楚。在这项研究中，我们重点关注液泡 H+-ATP 酶 (V-ATP 酶)，它是负责维持溶酶体中酸性 pH 的主要质子泵。我们的结果表明，在 RDA 过程中，溶酶体摄取核酸与溶酶体内的酸性 pH 无关。用巴弗洛霉素 A1（一种有效的 V-ATP 酶抑制剂）处理的分离溶酶体不会降解，但会以与对照溶酶体相似的水平吸收 RNA。同样，编码V-ATP酶催化亚基A的基因Atp6v1a的敲低并不影响分离的溶酶体的RNA摄取能力。此外，我们证明分离的溶酶体摄取核酸需要消耗 ATP，尽管摄取过程不需要 V-ATP 酶。这些结果拓宽了我们对自噬核酸降解机制的理解。
RNautophagy/DNautophagy (RDA) is an autophagic process that refers to the direct uptake of nucleic acids by lysosomes for degradation. Autophagy relies on lysosomes and lysosomal acidification is crucial for the degradation of intracellular components. However, whether lysosomal acidification interferes with nucleic acid uptake during RDA is unclear. In this study, we focused on vacuolar H+-ATPase (V-ATPase), the major proton pump responsible for maintaining an acidic pH in lysosomes. Our results show that lysosomes take up nucleic acids independently of the intralysosomal acidic pH during RDA. Isolated lysosomes treated with bafilomycin A1, a potent V-ATPase inhibitor, did not degrade, but took up RNA at similar levels as the control lysosomes. Similarly, the knockdown ofAtp6v1a, the gene that encodes V-ATPase catalytic subunit A, did not affect the RNA uptake ability of isolated lysosomes. In addition, we demonstrated that nucleic acid uptake by isolated lysosomes necessitates ATP consumption, although V-ATPase is not required for the uptake process. These results broaden our understanding of the mechanisms underlying nucleic acid degradation via autophagy.