Bacterial FtsZ induces mitochondrial fission in human cells

Abstract

32Mitochondria are key eukaryotic organelles that evolved from an intracellular bacterium, 33 in a process involving bacterial genome rearrangement and streamlining. As 34 mitochondria cannot form de novo, their biogenesis relies on growth and division. In 35 human cells, mitochondrial division plays an important role in processes as diverse as 36 mtDNA distribution, mitochondrial transport and quality control. Consequently, defects 37 in mitochondrial division have been associated with a wide range of human pathologies. 38While several protists have retained key components of the bacterial division machinery, 39 none have been detected in human mitochondria, where the dynamin-related protein 40 Drp1, a cytosolic GTPase is recruited to the mitochondrial outer membrane, forming 41 helical oligomers that constrict and divide mitochondria. Here, we created a human codon 42 optimized version of FtsZ, the central component of the bacterial division machinery, and 43 fused it to a mitochondrial targeting sequence. Upon expression in human cells, mt-FtsZ 44 was imported into the mitochondrial matrix, specifically localizing at fission sites prior to 45Drp1 and significantly increasing mitochondrial fission levels. Our data suggests that 46 human mitochondria have an internal, matrix-localized fission machinery, whose 47 structure is sufficiently conserved as to accommodate bacterial FtsZ. We identified 48 interaction partners of mt-FtsZ, and show that expression of PGAM5, FAM210, SFXN3 and 49 MTCH1 induced mitochondrial fission. Our results thus represent an innovative approach 50 for the discovery of novel critical mitochondrial fission components. 51 52 53

The Similarities between Human Mitochondria and Bacteria in the Context of Structure, Genome, and Base Excision Repair System

“…This hypothesis was tested by creating constructs and directing an α-proteobacterial FtsZ protein to the mitochondrial matrix. The authors show that FtsZ localized at fission sites and increased the rate of mitochondrial fission [ 77 ].…”

Light-inducible Deformation of Mitochondria in Live Cells

“…Different types of light-inducible protein-protein interactions, such as heterodimerization and homo-interaction, have been widely used to control biological activities including gene expression [11][12][13][14] and signaling transduction [15][16][17][18][19][20][21] . In a very recent study, an optical tool based on a bacterial actin nucleation promoting factor has been developed to trigger actin polymerization and thus generate compressing force to deform mitochondria 22 . The mechanical force provided by molecular motors, a class of natural force-generating protein molecules that mobilize on the cytoskeleton, has been manipulated by light to drive the intracellular movement of organelles via light-inducible association between organelles and molecular motors [23][24][25] .…”