Molecular mechanism of detectable catalase-containing particles, peroxisomes, in fibroblasts from a PEX2-defective patient.
Biochem Biophys Res Commun
; 268(1): 31-5, 2000 Feb 05.
Article
in En
| MEDLINE
| ID: mdl-10652207
ABSTRACT
Patients with peroxisome biogenesis disorders (PBD) can be identified by detection of peroxisomes in their fibroblasts, by means of immunocytochemical staining using an anti-catalase antibody. We report here data on three PBD patients with newly identified mutations (del550C and del642G) in the PEX2 gene which encodes a 35-kDa peroxisomal membrane protein containing two membrane-spanning and a C-terminal cysteine-rich region. Some of the fibroblasts from the patient with the del642G mutation contained numerous catalase-containing particles, whereas no fibroblasts containing such particles were found in the patient with the del550C mutation. We confirmed that the del642G mutation caused a partial defect in peroxisome synthesis and import by expression of the mutated PEX2 into PEX2-defective CHO mutant cells. We propose that the two putative membrane-spanning segments in Pex2p are important domains for peroxisome assembly and import and that a defect in one of these domains severely affects PBD patients. Furthermore, a defect in the C-terminal portion of Pex2p exposed to the cytosol containing a RING finger motif caused the mild phenotype, residual enzyme activities, and mosaic detectable peroxisomes in fibroblasts from the patient.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Catalase
/
Sequence Deletion
/
Peroxisomal Disorders
/
Peroxisomes
/
Membrane Proteins
Type of study:
Prognostic_studies
Limits:
Animals
/
Child, preschool
/
Female
/
Humans
/
Infant
Language:
En
Journal:
Biochem Biophys Res Commun
Year:
2000
Document type:
Article
Affiliation country: