Hi guys,
Last Monday I had a poster presentation for my Biol 108 course lab section. I would like to share some information about this presentation with you guys.The topic of the presentation is mitochondrial biogenesis. Nisoli and Carruba mentioned in their essay that metabolically active cells, such as liver, kidney, muscle and brain cells, contain hundreds or thousands of mitochondria, which make up ~40% of the cytoplasm.There are said to be 10 million billion mitochondria in an adult human (i.e. ~10% of our body weight) (Nisoli et. 2006). 10% of your body weight!!! Mitochondrial biogenesis is about the formation of new mitochondria due to the reproduction of mitochondria or the changes of the shape of mitochondria. I had focused specifically on the dynamic nature of the mitochondria in my presentation, and talked about the fission and fusion processes of mitochondria. Since I cannot post the information directly from my poster, I wrote a draft about my presentation and share with u guys.
Mitochondria are in constant movement within cells, and numerous fission and fusion events take place. These are accompanied by variations in mitochondrial size, number and mass. These events are triggered by many physiological stimuli and differentiation states. Mitochondria branch, stretch, retract and may even roll and unroll. At any given moment, they can be considered to be in a state of transition.1. Mitochondrial fusion. Fusion of mitochondria requires the sequential interaction of outer and inner membranes. Fusion of the outer membranes of two adjacent mitochondria requires low GTP levels, whereas the subsequent fusion of the inner membranes requires high GTP levels. As you can see from this picture, two mitochondria fuse together into one mitochondria in a larger size.Mitochondrial fission. Drp 1 protein in red color stands for dynamic related protein, and Fis 1 protein stand for Fission protein. Both of them are nuclear encoded proteins, not encoded inside the mitochondria by mtDNA---some nuclear encoded proteins are helping mitochondria complete the process of fission. Fission protein is localized to the mitochondrial outer membrane, whereas dynamic related protein is localized to the cytosol and punctate spots on mitochondria membrane. Some of these spots are constriction places that lead to mitochondrial fission. Dynamic related proteins form the ring to cut the mitochondria into two parts in the fission process.However, how dynamin related protein is recruited to mitochondria is unclear. We don`t know if dynamin related protein is attracted by mitochondria or it comes actively. The dynamic nature of mitochondria might protect them by ensuring that regional losses of membrane that caused by local depletion of metabolic substrates or mtDNA, are always transient. In particular, mitochondrial fusion enables intermitochondrial cooperation by allowing exchange of membrane and matrix components; Therefore, it can help to restore local depletion and maintain functions of mitochondria.
Enzo Nisoli and Michele O. Carruba also have done many researches about mitochondria biogenesis and its connection with Nitric Oxide. If you are curious about my field of study, click that link, there will be lots of information. See u guys!
Last Monday I had a poster presentation for my Biol 108 course lab section. I would like to share some information about this presentation with you guys.The topic of the presentation is mitochondrial biogenesis. Nisoli and Carruba mentioned in their essay that metabolically active cells, such as liver, kidney, muscle and brain cells, contain hundreds or thousands of mitochondria, which make up ~40% of the cytoplasm.There are said to be 10 million billion mitochondria in an adult human (i.e. ~10% of our body weight) (Nisoli et. 2006). 10% of your body weight!!! Mitochondrial biogenesis is about the formation of new mitochondria due to the reproduction of mitochondria or the changes of the shape of mitochondria. I had focused specifically on the dynamic nature of the mitochondria in my presentation, and talked about the fission and fusion processes of mitochondria. Since I cannot post the information directly from my poster, I wrote a draft about my presentation and share with u guys.
Mitochondria are in constant movement within cells, and numerous fission and fusion events take place. These are accompanied by variations in mitochondrial size, number and mass. These events are triggered by many physiological stimuli and differentiation states. Mitochondria branch, stretch, retract and may even roll and unroll. At any given moment, they can be considered to be in a state of transition.1. Mitochondrial fusion. Fusion of mitochondria requires the sequential interaction of outer and inner membranes. Fusion of the outer membranes of two adjacent mitochondria requires low GTP levels, whereas the subsequent fusion of the inner membranes requires high GTP levels. As you can see from this picture, two mitochondria fuse together into one mitochondria in a larger size.Mitochondrial fission. Drp 1 protein in red color stands for dynamic related protein, and Fis 1 protein stand for Fission protein. Both of them are nuclear encoded proteins, not encoded inside the mitochondria by mtDNA---some nuclear encoded proteins are helping mitochondria complete the process of fission. Fission protein is localized to the mitochondrial outer membrane, whereas dynamic related protein is localized to the cytosol and punctate spots on mitochondria membrane. Some of these spots are constriction places that lead to mitochondrial fission. Dynamic related proteins form the ring to cut the mitochondria into two parts in the fission process.However, how dynamin related protein is recruited to mitochondria is unclear. We don`t know if dynamin related protein is attracted by mitochondria or it comes actively. The dynamic nature of mitochondria might protect them by ensuring that regional losses of membrane that caused by local depletion of metabolic substrates or mtDNA, are always transient. In particular, mitochondrial fusion enables intermitochondrial cooperation by allowing exchange of membrane and matrix components; Therefore, it can help to restore local depletion and maintain functions of mitochondria.
Enzo Nisoli and Michele O. Carruba also have done many researches about mitochondria biogenesis and its connection with Nitric Oxide. If you are curious about my field of study, click that link, there will be lots of information. See u guys!
