Chen Haihong, Hu Yiyi, Yang Guanpin, Li Pingping, Yin Jingru, Feng Xiaoqing, Wu Qiong, Zhang Jingyu, Xiao Baoheng, Sui Zhenghong
Key Laboratory of Marine Genetics and Breeding, Ocean University of China, Qingdao, China.
Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, China.
Front Plant Sci. 2023 Sep 26;14:1225675. doi: 10.3389/fpls.2023.1225675. eCollection 2023.
Macropinocytosis is an endocytic process that plays an important role in animal development and disease occurrence but until now has been rarely reported in organisms with cell walls. We investigated the properties of endocytosis in a red alga, . The cells non-selectively internalized extracellular fluid into large-scale endocytic vesicles (1.94 ± 0.51 μm), and this process could be inhibited by 5-(N-ethyl-N-isopropyl) amiloride, an macropinocytosis inhibitor. Moreover, endocytosis was driven by F-actin, which promotes formation of ruffles and cups from the cell surface and facilitates formation of endocytotic vesicles. After vesicle formation, endocytic vesicles could be acidified and acquire digestive function. These results indicated macropinocytosis in . Abundant phosphatidylinositol kinase and small GTPase encoding genes were found in the genome of this alga, while PI3K, Ras, and Rab5, the important participators of traditional macropinocytosis, seem to be lacked. Such findings provide a new insight into endocytosis in organisms with cell walls and facilitate further research into the core regulatory mechanisms and evolution of macropinocytosis.
巨胞饮作用是一种内吞过程，在动物发育和疾病发生中起重要作用，但迄今为止在有细胞壁的生物体中鲜有报道。我们研究了一种红藻中的内吞作用特性。这些细胞将细胞外液非选择性地内化到大规模的内吞小泡（1.94±0.51μm）中，并且这个过程可被巨胞饮作用抑制剂5-（N-乙基-N-异丙基）氨氯吡咪抑制。此外，内吞作用由F-肌动蛋白驱动，F-肌动蛋白促进从细胞表面形成褶皱和杯状结构，并有助于内吞小泡的形成。小泡形成后，内吞小泡可被酸化并获得消化功能。这些结果表明该红藻中存在巨胞饮作用。在这种藻类的基因组中发现了丰富的磷脂酰肌醇激酶和小GTP酶编码基因，而传统巨胞饮作用的重要参与者PI3K、Ras和Rab5似乎并不存在。这些发现为有细胞壁生物体的内吞作用提供了新的见解，并有助于进一步研究巨胞饮作用的核心调控机制和进化。
