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Full-Text Articles in Life Sciences
Mitochondrial Division: Synergizing In Mitochondrial Divisome, Ao Liu
Mitochondrial Division: Synergizing In Mitochondrial Divisome, Ao Liu
Dartmouth College Ph.D Dissertations
Mitochondria are the energy factories of the cell. The dynamic nature of cells demands routine changes in mitochondrial morphology by fusion and division. The dynamin GTPase Drp1 is a central mitochondrial division protein, driving constriction of the outer mitochondrial membrane via oligomerization. At least four regulatory factors control Drp1 activity on the outer mitochondrial membrane (OMM): 1) receptor proteins (Mff, MiD49, MiD51, and Fis1); 2) actin filaments; 3) the mitochondrial phospholipid cardiolipin (CL); and 4) Drp1 post-translational modifications, of which two phosphorylation sites (S579 and S600) are the most well studied. However, the molecular mechanism of how these factors work …
Mechanisms And Roles Of Dynamic Actin Assembly Around Dysfunctional Mitochondria, Tak Shun Fung
Mechanisms And Roles Of Dynamic Actin Assembly Around Dysfunctional Mitochondria, Tak Shun Fung
Dartmouth College Ph.D Dissertations
Possessing the ability to efficiently generate ATP required to sustain cellular functions, mitochondria are often considered the ‘powerhouses of the cell’. However, our understanding of mitochondria in cell biology was further expanded when we recognized that communication between this unique organelle and the rest of the cell regulates cellular bioenergetics, metabolism and signaling processes such as mitophagy and apoptosis. Here, I investigate signaling between mitochondria and the actin cytoskeleton, and how this signaling regulates mitochondrial dynamics and cellular function. Specifically, I find that, upon mitochondrial dysfunction, actin polymerizes rapidly around the dysfunctional organelle, which we term ‘acute damage-induced actin’ (ADA). …
Novel Functions For Arp2/3 Complex-Mediated Actin Networks Discovered In Chlamydomonas Reinhardtii, Brae M. Bigge
Novel Functions For Arp2/3 Complex-Mediated Actin Networks Discovered In Chlamydomonas Reinhardtii, Brae M. Bigge
Dartmouth College Ph.D Dissertations
Chlamydomonas reinhardtii, a unicellular member of the Chlorophyta or Green Algae phylum, has been used for decades as a model for ciliary studies. Using this tool, previous work from our lab found a role for actin in ciliary assembly and maintenance. However, while the microtubule-based, membrane-ensheathed cilia of Chlamydomonas are highly conserved in relation to mammalian cells, the actin cytoskeleton is not as simple. Chlamydomonas contains two actin genes: IDA5, a conventional actin, and NAP1, a divergent actin. Here, we find that despite the divergence of NAP1, it is still able to interact with the actin nucleator, the Arp2/3 complex. …