10 functions of mitochondria

Mitochondria are essential intracellular organelles whose central role in maintaining energy homeostasis places them at the heart of cell integrity, function and survival. As the reliable provision of energy is so fundamental to every aspect of cellular function, mitochondrial dysfunction inevitably has devastating implications for the cell, the tissue and the organism. This is especially critical in the nervous system, where subtle changes in signalling and function can have catastrophic global consequences. Further, as postmitotic cells are heavily dependent on oxidative phosphorylation and are morphologically enormously complex, neurons pose a unique set of challenges for the mitochondrial population that reside within them. Mitochondrial dysfunction has profound consequences for the nervous system and is implicated in a host of neurological and neurodegenerative diseases. The following chapter introduces the form and function of these fascinating organelles and introduces key concepts and vulnerabilities that may underlie their involvement in neurodegenerative conditions. This introduction lays the foundation for the following chapters, which will explore specific aspects of the roles of these organelles in a range of neurodegenerative disease. Keywords • Mitochondria • Mitochondrial function • mtDNA genetics • Neurodegeneration • Margulis L, editor. Origin of eukaryotic cells. New Haven: Yale University Press; 1970. • Martin W, Mentel M. The origin of mitochondria. Na...

• Mitochondria are dynamic organelles. They continually fuse and divide, are actively recruited to specific cellular locations and have dynamic structures. • Mitochondrial fusion requires three large GTPases: the outer membrane proteins MFN1 and MFN2, and the inner membrane protein OPA1. • Mitochondrial fission requires the dynamin GTPase DRP1 and the outer membrane protein FIS1. • The fusion and fission of mitochondria have several important functions. These processes control the morphology of mitochondria, allow content exchange between mitochondria, control mitochondrial distribution and facilitate the release of intermembrane space proteins during apoptosis. • Several structural changes in mitochondria are important for rapid and efficient apoptosis: the mitochondria must be fragmented, their outer membranes must become permeable and the cristae junctions must be widened. • Mitochondrial dynamics is particularly important to neurons, and defects result in neurodegenerative disease. Recent findings have sparked renewed appreciation for the remarkably dynamic nature of mitochondria. These organelles constantly fuse and divide, and are actively transported to specific subcellular locations. These dynamic processes are essential for mammalian development, and defects lead to neurodegenerative disease. But what are the molecular mechanisms that control mitochondrial dynamics, and why are they important for mitochondrial function? We review these issues and explore how defec...

Mitochondria are essential for the viability of eukaryotic cells as they perform crucial functions in bioenergetics, metabolism and signalling and have been associated with numerous diseases. Recent functional and proteomic studies have revealed the remarkable complexity of mitochondrial protein organization. Protein machineries with diverse functions such as protein translocation, respiration, metabolite transport, protein quality control and the control of membrane architecture interact with each other in dynamic networks. In this Review, we discuss the emerging role of the mitochondrial protein import machinery as a key organizer of these mitochondrial protein networks. The preprotein translocases that reside on the mitochondrial membranes not only function during organelle biogenesis to deliver newly synthesized proteins to their final mitochondrial destination but also cooperate with numerous other mitochondrial protein complexes that perform a wide range of functions. Moreover, these protein networks form membrane contact sites, for example, with the endoplasmic reticulum, that are key for integration of mitochondria with cellular function, and defects in protein import can lead to diseases. Open Access articles citing this article. • • Cheryl Zi Jin Phua • , Xiaqing Zhao • … Alaattin Kaya GeroScience Open Access 22 April 2023 • • Uwe Schulte • , Fabian den Brave • … Thomas Becker Nature Open Access 25 January 2023 • • Elias Adriaenssens • , Bob Asselbergh • … Vincen...

Mitochondria are critical to cellular metabolism, homeostasis and stress responses, and their dysfunction is linked to human disease and pathology. In this issue, we present a Focus of specially commissioned Review articles that discuss recent discoveries and emerging questions in this rapidly advancing field. Mitochondria have long been considered the power stations of the eukaryotic cell, producing the basic unit of cellular energy, ATP, through oxidative phosphorylation. Beyond ATP production, mitochondria maintain ion homeostasis, produce precursors for macromolecules, such as lipids, proteins, and DNA, and generate and sequester potentially damaging metabolic byproducts such as ammonia and reactive oxygen species. In addition, mitochondria are now understood to play active roles in integrating signalling pathways and responses to stressors. Mitochondria are dynamic and their functions have been tightly linked to their fission and fusion, motility, positioning, and form. Recent research has begun to uncover the broad reach of mitochondria in cellular communication through signalling pathways and contacts with other organelles, such as autophagosomes, endoplasmic reticulum, lysosomes and the nucleus. Mitochondrial function and dysfunction have emerged as key factors in mediating metabolic disease, cancer cell metabolism, neurodegeneration and aging, illustrating how mitochondria contribute to health and pathology. To highlight recent advances and emerging questions in t...

Functions of Mitochondria Citric Acid Cycle During oxidation, pyruvate is converted to acetyl-CoA, which then undergoes further metabolic to produce carbon dioxide, NADH, and FADH2. Transferred fatty acids are metabolized to acetyl-CoA in the mitochondrial matrix before entering the citric acid cycle. Next, the electron transport chain inside the inner mitochondrial membrane uses NADH and FADH to produce enough ATP for the cell. What is the function of cristae in mitochondria? Mitochondrial DNA Mitochondrial DNA is included in the matrix as well, giving the mitochondria a degree of autonomy. Mitochondrial DNA is circular, like bacterial DNA. It has just 37 genes, some of which code for DNA RNA genes and others for enzymes involved in ATP synthesis (the cellular energy molecule). Nuclear DNA, rather than mitochondrial DNA, encodes the vast majority of the proteins necessary for cellular respiration and ATP generation. Mutations in mitochondrial genes may result in a wide range of illnesses, including blindness in humans in the form of Leper genetic optic neuropathy. Mitochondrial RNA All of the machinery required to convert the mitochondrial DNA into proteins is housed in the mitochondrial matrix. RNA (transfer RNA, ribosomal RNA, rRNA) is the genetic material that is translated into ribosome molecules or complexes. This RNA employs a variant of the genetic code used by cytoplasmic RNA. Just around 22 R-R are encoded by the mitochondrial DNA, yet they are the only RNAs capa...