Molecular characterization of gene expression in human lactate dehydrogenase-A deficiency.
Recurrent rhabdomyolysis due to decreased glycolysis occurred during strenuous exercise in patients with lactate dehydrogenase-A-subunit (LDH-A; muscle) deficiency. Enzyme activities of LDH in the muscle were decreased less than 8% of the control value. The isozyme pattern revealed only one band of B4. The level of LDH-A mRNA was not decreased. The direct sequencing of the reverse transcription-polymerase chain reaction product that corresponds to exon 6 revealed a deletion of 20 nucleotides. Immunofluorescence staining showed the presence of LDH-A protein within the cytoplasm. These findings suggest that an incomplete LDH-A protein lacking the subunit contact subdomain could not assemble into a tetrameric structure that has an enzymatic activity.
Miyajima
H
H
First Department of Medicine, Hamamatsu University School of Medicine, Japan.
Takahashi
Y
Y
Suzuki
M
M
Shimizu
T
T
Kaneko
E
E
D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000172:deficiency / Q000235:genetics*; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
D007527:Isoenzymes; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D007770:L-Lactate Dehydrogenase