Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK.
Microbiologyopen. 2020 Feb;9(2):e969. doi: 10.1002/mbo3.969. Epub 2019 Nov 19.
The Leishmania lysosome has an atypical structure, consisting of an elongated vesicle-filled tubule running along the anterior-posterior axis of the cell, which is termed the multivesicular tubule (MVT) lysosome. Alongside, the MVT lysosome is one or more microtubules, the lysosomal microtubule(s). Previous work indicated there were cell cycle-related changes in MVT lysosome organization; however, these only provided snapshots and did not connect the changes in the lysosomal microtubule(s) or lysosomal function. Using mNeonGreen tagged cysteine peptidase A and SPEF1 as markers of the MVT lysosome and lysosomal microtubule(s), we examined the dynamics of these structures through the cell cycle. Both the MVT lysosome and lysosomal microtubule(s) elongated at the beginning of the cell cycle before plateauing and then disassembling in late G before cytokinesis. Moreover, the endocytic rate in cells where the MVT lysosome and lysosomal microtubule(s) had disassembled was extremely low. The dynamic nature of the MVT lysosome and lysosomal microtubule(s) parallels that of the Trypanosoma cruzi cytostome/cytopharynx, which also has a similar membrane tubule structure with associated microtubules. As the cytostome/cytopharynx is an ancestral feature of the kinetoplastids, this suggests that the Leishmania MVT lysosome and lysosomal microtubule(s) are a reduced cytostome/cytopharynx-like feature.
利什曼虫溶酶体具有非典型的结构，由一个沿细胞前后轴延伸的充满囊泡的管状结构组成，称为多泡管状溶酶体（MVT）溶酶体。此外，MVT 溶酶体还有一个或多个微管，即溶酶体微管。先前的工作表明，MVT 溶酶体的结构在细胞周期中发生相关变化；然而，这些变化仅提供了静态快照，并未将溶酶体微管或溶酶体功能的变化联系起来。我们使用标记有 mNeonGreen 的半胱氨酸肽酶 A 和 SPEF1 作为 MVT 溶酶体和溶酶体微管的标志物，通过细胞周期来研究这些结构的动态变化。在细胞周期开始时，MVT 溶酶体和溶酶体微管均伸长，然后在后期 G 时达到平台期并解体，最后在细胞分裂时解体。此外，在 MVT 溶酶体和溶酶体微管已经解体的细胞中，内吞作用的速率极低。MVT 溶酶体和溶酶体微管的动态性质与克氏锥虫胞口/胞咽的动态性质相似，后者也具有类似的膜管状结构和相关的微管。由于胞口/胞咽是动基体门的一个古老特征，这表明利什曼虫的 MVT 溶酶体和溶酶体微管是一种简化的胞口/胞咽样特征。
