Mitochondrial Proteases
Mitochondrial Proteases - Related Videos
09:00
Use of the Protease Fluorescent Detection Kit to Determine Protease Activity
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Cited by 15 •
2009
The Protease Fluorescent Detection Kit is designed for the measurement of protease activity using fluorometry. It is also suitable for detection of trace amounts of protease contamination. The method is based on the proteolytic hydroysis of a proprietary formulation of a FITC-labeled casein substrate.
08:14
Determining Membrane Protein Topology Using Fluorescence Protease Protection (FPP)
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Cited by 18 •
2015
Here, we present a protocol to determine the orientation and topology of integral membrane proteins in living cells. This simple protocol relies on selective protease sensitivity of chimeras between the protein of interest and GFP.
05:53
Mitochondrial Ca2+ Retention Capacity Assay and Ca2+-triggered Mitochondrial Swelling Assay
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Cited by 11 •
2018
This protocol aims to describe a method to examine the Ca2+ retention capacity and Ca2+- triggered mitochondrial swelling of isolated mitochondria of SH-SY5Y cells step-by-step.
11:37
Sigma's Non-specific Protease Activity Assay - Casein as a Substrate
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Cited by 414 •
2008
Proteases break peptide bonds. In the lab, it is often necessary to measure and/or compare the activity of proteases. Sigma's non-specific protease activity assay may be used as a standardized procedure to determine the activity of proteases.
02:59
Animal Mitochondrial Genetics
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2020
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
FAQs
ATP-dependent AAA proteases couple energy use to substrate handling. They recognize selected proteins, use ATP to unfold them, and then drive their degradation rather than simply cleaving an already unfolded chain. This mechanism is important for removing damaged or misfolded proteins and for controlling protein abundance within mitochondria, especially when cellular stress challenges protein quality control.
Processing peptidases activate newly imported mitochondrial proteins by removing their targeting sequences. ATP-dependent AAA proteases instead use energy to unfold and degrade selected substrates. The distinction is functional: one pathway enables maturation of imported precursors, whereas the other regulates protein disposal. Together, these activities help establish an appropriate mitochondrial protein composition.
Regulated proteolysis prevents mitochondrial protein composition from being determined only by protein synthesis and import. Processing peptidases mature useful precursors, while degradation pathways remove damaged or misfolded proteins. This balance supports organelle maintenance and helps mitochondria respond to cellular stress without allowing defective proteins to accumulate unchecked.
Proteolytic processing helps newly imported proteins reach functional forms, while selective degradation removes proteins that are damaged or unsuitable for continued use. By coordinating maturation and turnover, mitochondrial proteases contribute to respiratory-chain assembly and preserve the protein organization needed for cellular energy metabolism. Defects in these controls can therefore affect both organelle maintenance and energy-related function.
After a protein precursor is imported into mitochondria, a processing peptidase can remove its targeting sequence and activate the protein. The resulting mature protein can contribute to mitochondrial functions, whereas damaged or misfolded proteins are directed toward regulated degradation. This sequence links import, maturation, and quality control within the same organelle.
Mitochondrial proteases provide a biochemical framework for connecting protein turnover with broader cellular outcomes. Researchers can examine how defective processing or degradation alters mitochondrial maintenance, respiratory-chain assembly, and responses to stress. These relationships make the proteases relevant to studies of apoptosis, aging, and disorders associated with defective protein turnover.