scholarly journals Small GTPase CDC-42 promotes apoptotic cell corpse clearance in response to PAT-2 and CED-1 in C. elegans

2014 ◽  
Vol 21 (6) ◽  
pp. 845-853 ◽  
Author(s):  
L J Neukomm ◽  
S Zeng ◽  
A P Frei ◽  
P A Huegli ◽  
M O Hengartner
Development ◽  
2011 ◽  
Vol 138 (10) ◽  
pp. 2003-2014 ◽  
Author(s):  
L. J. Neukomm ◽  
A.-S. Nicot ◽  
J. M. Kinchen ◽  
J. Almendinger ◽  
S. M. Pinto ◽  
...  

2017 ◽  
Vol 216 (6) ◽  
pp. 1775-1794 ◽  
Author(s):  
Jianhua Yin ◽  
Yaling Huang ◽  
Pengfei Guo ◽  
Siqi Hu ◽  
Sawako Yoshina ◽  
...  

Apoptotic cells generated by programmed cell death are engulfed by phagocytes and enclosed within plasma membrane–derived phagosomes. Maturation of phagosomes involves a series of membrane-remodeling events that are governed by the sequential actions of Rab GTPases and lead to formation of phagolysosomes, where cell corpses are degraded. Here we identified gop-1 as a novel regulator of apoptotic cell clearance in Caenorhabditis elegans. Loss of gop-1 affects phagosome maturation through the RAB-5–positive stage, causing defects in phagosome acidification and phagolysosome formation, phenotypes identical to and unaffected by loss of unc-108, the C. elegans Rab2. GOP-1 transiently associates with cell corpse–containing phagosomes, and loss of its function abrogates phagosomal association of UNC-108. GOP-1 interacts with GDP-bound and nucleotide-free UNC-108/Rab2, disrupts GDI-UNC-108 complexes, and promotes activation and membrane recruitment of UNC-108/Rab2 in vitro. Loss of gop-1 also abolishes association of UNC-108 with endosomes, causing defects in endosome and dense core vesicle maturation. Thus, GOP-1 is an activator of UNC-108/Rab2 in multiple processes.


Autophagy ◽  
2012 ◽  
Vol 8 (8) ◽  
pp. 1267-1268 ◽  
Author(s):  
Wei Zou ◽  
Xiaochen Wang ◽  
Ronald Vale ◽  
Guangshuo Ou

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4475-4488 ◽  
Author(s):  
Erik A. Lundquist ◽  
Peter W. Reddien ◽  
Erika Hartwieg ◽  
H. Robert Horvitz ◽  
Cornelia I. Bargmann

The Caenorhabditis elegans genome contains three rac-like genes, ced-10, mig-2, and rac-2. We report that ced-10, mig-2 and rac-2 act redundantly in axon pathfinding: inactivating one gene had little effect, but inactivating two or more genes perturbed both axon outgrowth and guidance. mig-2 and ced-10 also have redundant functions in some cell migrations. By contrast, ced-10 is uniquely required for cell-corpse phagocytosis, and mig-2 and rac-2 have only subtle roles in this process. Rac activators are also used differentially. The UNC-73 Trio Rac GTP exchange factor affected all Rac pathways in axon pathfinding and cell migration but did not affect cell-corpse phagocytosis. CED-5 DOCK180, which acts with CED-10 Rac in cell-corpse phagocytosis, acted with MIG-2 but not CED-10 in axon pathfinding. Thus, distinct regulatory proteins modulate Rac activation and function in different developmental processes.


eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
Omar Peña-Ramos ◽  
Lucia Chiao ◽  
Xianghua Liu ◽  
Xiaomeng Yu ◽  
Tianyou Yao ◽  
...  

Autophagosomes are double-membrane intracellular vesicles that degrade protein aggregates, intracellular organelles, and other cellular components. During the development of the nematode Caenorhabditis elegans, many somatic and germ cells undergo apoptosis. These cells are engulfed and degraded by their neighboring cells. We discovered a novel role of autophagosomes in facilitating the degradation of apoptotic cells using a real-time imaging technique. Specifically, the double-membrane autophagosomes in engulfing cells are recruited to the surfaces of phagosomes containing apoptotic cells and subsequently fuse to phagosomes, allowing the inner vesicle to enter the phagosomal lumen. Mutants defective in the production of autophagosomes display significant defects in the degradation of apoptotic cells, demonstrating the importance of autophagosomes to this process. The signaling pathway led by the phagocytic receptor CED-1, the adaptor protein CED-6, and the large GTPase dynamin (DYN-1) promotes the recruitment of autophagosomes to phagosomes. Moreover, the subsequent fusion of autophagosomes with phagosomes requires the functions of the small GTPase RAB-7 and the HOPS complex components. Further observations suggest that autophagosomes provide apoptotic cell-degradation activities in addition to and in parallel of lysosomes. Our findings reveal that, unlike the single-membrane, LC3-associated phagocytosis (LAP) vesicles reported for mammalian phagocytes, the canonical double-membrane autophagosomes facilitate the clearance of C. elegans apoptotic cells. These findings add autophagosomes to the collection of intracellular organelles that contribute to phagosome maturation, identify novel crosstalk between the autophagy and phagosome maturation pathways, and discover the upstream signaling molecules that initiate this crosstalk.


2017 ◽  
Vol 428 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Dou Wu ◽  
Yongping Chai ◽  
Zhiwen Zhu ◽  
Wenjing Li ◽  
Guangshuo Ou ◽  
...  

2019 ◽  
Vol 218 (8) ◽  
pp. 2619-2637 ◽  
Author(s):  
Qiwen Gan ◽  
Xin Wang ◽  
Qian Zhang ◽  
Qiuyuan Yin ◽  
Youli Jian ◽  
...  

Phagocytic removal of apoptotic cells involves formation, maturation, and digestion of cell corpse–containing phagosomes. The retrieval of lysosomal components following phagolysosomal digestion of cell corpses remains poorly understood. Here we reveal that the amino acid transporter SLC-36.1 is essential for lysosome reformation during cell corpse clearance in Caenorhabditis elegans embryos. Loss of slc-36.1 leads to formation of phagolysosomal vacuoles arising from cell corpse–containing phagosomes. In the absence of slc-36.1, phagosome maturation is not affected, but the retrieval of lysosomal components is inhibited. Moreover, loss of PPK-3, the C. elegans homologue of the PtdIns3P 5-kinase PIKfyve, similarly causes accumulation of phagolysosomal vacuoles that are defective in phagocytic lysosome reformation. SLC-36.1 and PPK-3 function in the same genetic pathway, and they directly interact with one another. In addition, loss of slc-36.1 and ppk-3 causes strong defects in autophagic lysosome reformation in adult animals. Our findings thus suggest that the PPK-3–SLC-36.1 axis plays a central role in both phagocytic and autophagic lysosome formation.


2014 ◽  
Vol 25 (13) ◽  
pp. 2071-2083 ◽  
Author(s):  
Meng Xu ◽  
Yubing Liu ◽  
Liyuan Zhao ◽  
Qiwen Gan ◽  
Xiaochen Wang ◽  
...  

During programmed cell death, the clearance of apoptotic cells is achieved by their phagocytosis and delivery to lysosomes for destruction in engulfing cells. However, the role of lysosomal proteases in cell corpse destruction is not understood. Here we report the identification of the lysosomal cathepsin CPL-1 as an indispensable protease for apoptotic cell removal in Caenorhabditis elegans. We find that loss of cpl-1 function leads to strong accumulation of germ cell corpses, which results from a failure in degradation rather than engulfment. CPL-1 is expressed in a variety of cell types, including engulfment cells, and its mutation does not affect the maturation of cell corpse–containing phagosomes, including phagosomal recruitment of maturation effectors and phagosome acidification. Of importance, we find that phagosomal recruitment and incorporation of CPL-1 occurs before digestion of cell corpses, which depends on factors required for phagolysosome formation. Using RNA interference, we further examine the role of other candidate lysosomal proteases in cell corpse clearance but find that they do not obviously affect this process. Collectively, these findings establish CPL-1 as the leading lysosomal protease required for elimination of apoptotic cells in C. elegans.


Development ◽  
2012 ◽  
Vol 139 (24) ◽  
pp. 4613-4622 ◽  
Author(s):  
J. Huang ◽  
H. Wang ◽  
Y. Chen ◽  
X. Wang ◽  
H. Zhang

2012 ◽  
Vol 125 (24) ◽  
pp. e1-e1
Author(s):  
J. Huang ◽  
H. Wang ◽  
Y. Chen ◽  
X. Wang ◽  
H. Zhang

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