CLPX
CLPX (caseinolytic mitochondrial matrix peptidase chaperone subunit X) is an ATP-dependent chaperone of the mitochondrial matrix that works as an unfoldase. It partners with the proteolytic subunit CLPP in the ClpXP protease and also acts in heme biosynthesis and mtDNA nucleoid control. Browse Assay Genie's current range of CLPX research reagents below, or read on for the biology behind the target.
CLPX is an ATP-dependent chaperone that functions as an unfoldase. As part of the ClpXP protease complex, it recognises specific protein substrates, unfolds them using energy from ATP hydrolysis, and translocates them to the proteolytic subunit CLPP for degradation. The assembled protease consists of two heptameric rings of the CLPP catalytic subunit sandwiched between two hexameric rings of the chaperone subunit encoded by the CLPX gene.
Beyond protein turnover, the chaperone activity of CLPX contributes to the incorporation of the pyridoxal phosphate cofactor into 5-aminolevulinate synthase. This activates 5-aminolevulinate (ALA) synthesis, the first step in heme biosynthesis. CLPX is also involved in controlling the distribution of mtDNA nucleoids, which it does by regulating the activity of mitochondrial transcription factor A (TFAM). Its localisation to the mitochondrial matrix and nucleoid fits these roles.
The CLPX protein belongs to the ClpX chaperone family and is classed by HGNC within the AAA ATPases and the mitochondrial nucleoid associated proteins. Its earlier names, ClpX (caseinolytic protease X, E. coli) homolog, reflect its relationship to the bacterial protein. The gene has two reported transcript variants, one protein-coding and one non-protein coding. Mouse and rat each have a Clpx ortholog, which makes rodent models relevant to studies of mitochondrial proteostasis.
CLPX unfolds specific substrates and passes them to CLPP, making it central to ATP-dependent protein degradation in the mitochondrial matrix.
CLPX chaperone activity supports pyridoxal phosphate incorporation into 5-aminolevulinate synthase, activating ALA synthesis, the first step of heme production.
CLPX helps control mtDNA nucleoid distribution by regulating TFAM activity, linking protein quality control to mitochondrial genome organisation.
Hexameric CLPX rings use ATP hydrolysis to unwind substrates, offering a model for studying unfoldase function within a protease complex.
CLPX is an ATP-dependent unfoldase in the mitochondrial matrix. Within the ClpXP protease it recognises substrates, unfolds them using ATP hydrolysis and passes them to CLPP for degradation. It also aids heme biosynthesis through 5-aminolevulinate synthase and regulates TFAM activity in mtDNA nucleoid distribution.
The UniProt name is ATP-dependent clpX-like chaperone, mitochondrial. Earlier HGNC names were ClpX (caseinolytic protease X, E. coli) homolog and ClpX caseinolytic protease X homolog (E. coli). No alternative gene symbols are listed. Two transcript variants exist, one protein-coding and one non-protein coding.
The name reflects homology to bacterial ClpX, and the protein belongs to the ClpX chaperone family. Mouse and rat both have a Clpx ortholog. For any product, check the datasheet for its validated reactivity before choosing a species.
Partner proteases, nucleoid factors and heme biosynthesis enzymes linked to CLPX function.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O76031; product specifications from Assay Genie datasheets.