Mitochondrial Markers

Common Mitochondrial Markers | Apoptosis | Oxidative Phosphorylation | Mitochondrial Dynamics | Additional Mitochondrial Markers

Common Mitochondrial Markers

What are Mitochondrial Marker Antibodies Used For?

In response to stress or other biological cues, a protein’s subcellular distribution can change, indicative of the physiological state of the cell or tissue. Mitochondrial markers are used as well-established references when investigating the localization of a protein of interest and in microscopy furnishes additional details about mitochondrial structure and morphology. Mitochondrial markers also serve as quality controls. The purity of protein extracts derived from subcellular fractionation (Mitochondrial Isolation Kit [NBP2-29448]) can be examined in Western Blot to assess potential cross contamination of fractions (e.x. nucleus, cytosol, and mitochondria). Bio-Techne offers numerous highly published, well validated antibodies for mitochondrial markers along with bright, photostable, fluorescent conjugates such as Janelia Fluor^® Dyes, for studying these complex, dynamic organelles. Janelia Fluor^® Dyes are optimal for live cell imaging and super resolution microscopy, enabling superior detection and analysis of cellular targets.

Apoptosis

Mitochondria play a crucial role in apoptosis, a form of programmed cell death, that is essential for establishing proper tissue homeostasis and is often dysregulated in cancer. The intrinsic/mitochondrial apoptosis pathway is initiated by factors including DNA damage and oxidative stress, leading to caspase activation and cell death. In mammals, apoptosis is a complex process largely regulated by the Bcl-2 family of proteins that are either pro-apoptotic (e.g. Bax, Bak) or anti-apoptotic (e.g. Bcl-2). In response to apoptotic stimuli, Bax/Bak become activated and Bax translocates to the mitochondria. The subsequent oligomerization of Bax/Bak promotes mitochondrial outer membrane permeabilization (MOMP), cytochrome c release and apoptosome formation. The resulting signaling cascade involving caspase-9 and caspase-3 activation ultimately leads to cell disassembly.

Oxidative Phosphorylation

The most well-known function of mitochondria is energy production in the form of ATP. In the mitochondria, the citric acid cycle produces ATP and the reduction of coenzymes NAD+ and FAD+. During oxidation, the transfer of electrons from these reduced coenzymes involves a series of four respiratory chain (also known as the electron transport chain, ETC) protein complexes (Complex I, II, III, and IV), which creates a proton gradient across the inner mitochondrial membrane. These four complexes and the ATP synthase of the OXPHOS system are comprised of multiple subunits with over 90+ structural proteins and 30+ assembly factors

*Note: This table is not an exhaustive list of all mitochondrial proteins involved in oxidative phosphorylation.

back to the top

Mitochondrial Dynamics

Mitochondrial dynamics refers to the ability of mitochondria to change shape, alter the inner and outer membrane structure, and exchange organelle components. The process of mitochondrial dynamics involves a coordination between fission and fusion events. Key components of the mitochondrial fission and fusion machinery include conserved GTPases in the dynamin family. Mitochondrial fission (mitochondrial fragmentation) is the process of generating multiple heterogeneous mitochondria from one mitochondrion. Conversely, mitochondrial fusion is the merging of two or more mitochondria to create a network.

Defective mitochondrial dynamics are a hallmark of many diseases, in particular for neurodegenerative disorders. A study by Wu et al. examined mitochondrial dysfunction in the context of Alzheimer’s disease (AD), finding altered mitochondrial morphology and significantly increased expression of key fusion proteins, including Mitofusin-1 (Mfn-1) (NBP1-71775) and Mitofusin-2 (Mfn-2). Wu et al. suggested excessive amyloid-beta (Aβ) accumulation leads to abnormal mitofusin expression and triggers mitochondrial dysfunction observed during AD pathogenesis.

back to the top

Additional Mitochondrial Markers

Mitochondria have additional functions ranging from protein translation, preprotein and protein import and export, protein folding and assembly, and regulation of cell cycle and growth. HSP60, a well-known mitochondrial chaperonin, is responsible for regulating proper protein folding and assembly of imported proteins. Prohibitin, a ubiquitously expressed, pleiotropic protein, is involved in mitochondrial biogenesis, metabolism, and morphology, and, its dysregulation has been linked to aging, metabolic, proliferative, and neurodegenerative diseases.

*Note: This table is not an exhaustive list of all mitochondrial proteins involved in oxidative phosphorylation.

back to the top