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Updated: Jul 31, 2026
07:38
Measuring In Vitro ATPase Activity for Enzymatic Characterization
Published on: August 23, 2016
ATP-dependent proteases in prokaryotic and eukaryotic cells
1Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, MA 02115.
Seminars in Cell Biology
|December 1, 1990
Summary
Cellular protein degradation relies on ATP-dependent proteases like E. coli protease La and the eukaryotic proteasome. These enzymes regulate protein breakdown, preventing cellular damage.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Intracellular proteolysis requires significant energy, primarily due to large, multimeric proteases utilizing ATP hydrolysis.
- Key ATP-dependent proteases include E. coli protease La, Ti (Clp), and the eukaryotic proteasome.
Purpose of the Study:
- To review the mechanisms and physiological roles of major ATP-dependent proteases.
- To highlight the energy requirements and regulatory strategies governing intracellular proteolysis.
Main Methods:
- Literature review of studies on bacterial and eukaryotic proteases.
- Analysis of enzyme structures, functions, and regulatory mechanisms.
Main Results:
- Protease La (E. coli) is a tetrameric enzyme activated by unfolded proteins, with tight transcriptional regulation.
- E. coli Ti (Clp) protease comprises distinct ATPase and proteolytic subunits.
- Eukaryotic proteasomes (650 kDa) are multicatalytic ATP-dependent proteases, forming larger complexes (e.g., 1300 kDa in muscle) with other proteases like multipain for ubiquitinated protein degradation.
Conclusions:
- ATP-dependent proteases are crucial for cellular protein homeostasis.
- Diverse mechanisms involving allosteric activation, subunit dissociation, and complex formation regulate protease activity.
- Further research is needed to fully elucidate the physiological roles and operational mechanisms of these complex proteolytic systems.
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