Potential role of Apoptosis Inducing Factor in evolutionarily significant eukaryote, Dictyostelium discoideum survival.
Apoptosis Inducing Factor (AIF), a phylogenetically conserved mitochondrial inter-membrane space flavoprotein has an important role in caspase independent cell death. Nevertheless, AIF is also essential for cell survival. It is required for mitochondrial organization and energy metabolism. Upon apoptotic stimulation, AIF induces DNA fragmentation after its mitochondrio-nuclear translocation. Although it executes critical cellular functions in a coordinated manner, the exact mechanism still remains obscure. The present study aims to understand AIF's role in cell survival, growth and development by its down-regulation in an interesting unicellular eukaryote, D. discoideum which exhibits multicellularity upon starvation. Constitutive AIF down-regulated (dR) cells exhibited slower growth and delayed developmental morphogenesis. Also, constitutive AIF dR cells manifested high intracellular ROS, oxidative DNA damage and calcium levels with lower ATP content. Interestingly, constitutive AIF dR cells showed amelioration in cell growth upon antioxidant treatment, strengthening its role as ROS regulator. Under oxidative stress, AIF dR cells showed early mitochondrial membrane depolarization followed by AIF translocation from mitochondria to nucleus and exhibited necrotic cell death as compared to paraptoptic cell death of control cells. Thus, the results of this study provide an exemplar where AIF is involved in growth and development by regulating ROS levels and maintaining mitochondrial function in D. discoideum, an evolutionarily significant model organism exhibiting caspase independent apoptosis.
Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India.
Ashlesha A
AA
Kadam
Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India.
Tina
T
Jubin
Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India.
Hina A
HA
Mir
Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India. Electronic address: rasheedunnisab@yahoo.co.in.
Rasheedunnisa
R
Begum
D000255:Adenosine Triphosphate / Q000378:metabolism; D017304:Annexin A5 / Q000378:metabolism; D051033:Apoptosis Inducing Factor / Q000378:metabolism*; D005075:Biological Evolution; D002118:Calcium / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004023:Dictyostelium / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D015536:Down-Regulation / Q000187:drug effects; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005470:Fluorometry; D005947:Glucose / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009243:NAD / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D011419:Propidium / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D016372:RNA, Antisense / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013194:Staining and Labeling
D017304:Annexin A5; D051033:Apoptosis Inducing Factor; D016372:RNA, Antisense; D017382:Reactive Oxygen Species; D009243:NAD; D011419:Propidium; D000255:Adenosine Triphosphate; D016650:Fluorescein-5-isothiocyanate; D005947:Glucose; D002118:Calcium
Apoptosis inducing factor; Dictyostelium discoideum; Mitochondrial membrane potential; Reactive oxygen species