title: Coordinated balance of Rac1 and RhoA plays key roles in determining phagocytic appetite.
abstract: The removal of unwanted or damaged cells by phagocytes is achieved via a finely regulated cleaning process called efferocytosis. To characterize the mechanisms through which phagocytes control the intake of apoptotic cells, we investigated how the phagocyte's appetite for engulfed cells may be coordinated by RhoA and Rac1 in the phagocytic cup. We used FRET biosensors to visualize the spatiotemporal dynamics of Rho-family GTPases, and found that RhoA, which is known to be downregulated during phagocytosis, was transiently upregulated at the phagocytic cup immediately prior to ingestion. Conversely, Rac1 was upregulated during the engulfment process and then downregulated prior to phagosomal maturation. Moreover, disturbance of the dynamic activities of RhoA led to uncontrolled engulfment, such as fast and undiscerning eating. Our results reveal that the temporal activity of RhoA GTPase alters the Rac1/RhoA balance at the phagocytic cup prior to ingestion, and that this plays a distinct role in orchestrating efferocytosis, with RhoA modulating the rate of engulfment to ensure that the phagocyte engulfs an appropriate amount of the correct material.
authors.affiliation: Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.|ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea.|Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang-Yeob
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Soyoun
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.|ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea.
authors.forename: Dong-Jun
authors.initials: DJ
authors.lastname: Bae
authors.affiliation: Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju, Republic of Korea.
authors.forename: Seung-Yoon
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Ga-Young
authors.initials: GY
authors.lastname: Lee
authors.affiliation: Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Gyeong-Min
authors.initials: GM
authors.lastname: Park
authors.affiliation: Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea.|KU-KIST school, Korea University, Seoul, Republic of Korea.
authors.forename: In-San
authors.identifier: http://orcid.org/0000-0003-1714-4521
authors.initials: IS
authors.lastname: Kim
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015374:Biosensing Techniques; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D007739:L Cells; D017737:Macrophages, Peritoneal / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D010586:Phagocytes / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology*; D059008:Time-Lapse Imaging; D020830:rac1 GTP-Binding Protein / Q000502:physiology*; D020742:rhoA GTP-Binding Protein / Q000502:physiology*
chemical_list: D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein