Human mitochondrial ClpP is a stable heptamer that assembles into a tetradecamer in the presence of ClpX SCIE SCOPUS

Cited 69 time in WEB OF SCIENCE Cited 73 time in Scopus
Title
Human mitochondrial ClpP is a stable heptamer that assembles into a tetradecamer in the presence of ClpX
Author(s)
Kang, S.G.; Dimitrova, M.N.; Ortega, J.; Ginsburg, A.; Maurizi, M.R.
KIOST Author(s)
Kang, Sung Gyun(강성균)
Publication Year
2005-10
Abstract
The functional form of ClpP, the proteolytic component of ATP-dependent Clp proteases, is a hollow-cored particle composed of two heptameric rings joined face-to-face forming an aqueous chamber containing the proteolytic active sites. We have found that isolated human mitochondrial ClpP (hClpP) is stable as a heptamer and remains a monodisperse species (s20,w 7.0 S; M app 169, 200) at concentrations ≥3 mg/ml. Heptameric hClpP has no proteolytic activity and very low peptidase activity. In the presence of ATP, hClpX interacts with hClpP forming a complex, which by equilibrium sedimentation measurements has a Mapp of 1 × 106. Electron microscopy confirmed that the complex consisted of a double ring of hClpP with an hClpX ring axially aligned on each end. The hClpXP complex has protease activity and greatly increased peptidase activity, indicating that interaction with hClpX affects the conformation of the hClpP catalytic active site. A mutant of hClpP, in which a cysteine residue was introduced into the handle region at the interface between the two rings formed stable tetradecamers under oxidizing conditions but spontaneously dissociated into two heptamers upon reduction. Thus, hClpP rings interact transiently but very weakly in solution, and hClpX must exert an allosteric effect on hClpP to promote a conformation that stabilizes the tetradecamer. These data suggest that hClpX can regulate the appearance of hClpP peptidase activity in mitochondria and might affect the nature of the degradation products released during ATP-dependent proteolytic cycles.
ISSN
0021-9258
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/5018
DOI
10.1074/jbc.M507240200
Bibliographic Citation
Journal of Biological Chemistry, v.280, no.42, pp.35424 - 35432, 2005
Publisher
American Society for Biochemistry and Molecular Biology Inc.
Type
Article
Language
English
Document Type
Article
Publisher
American Society for Biochemistry and Molecular Biology Inc.
Related Researcher
Research Interests

marine biotechnology,microbiology,해양생명공학,미생물학

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