Is antiquitin a mitochondrial Enzyme?
Antiquitin is an aldehyde dehydrogenase involved in the catabolism of lysine. Mutations of antiquitin have been linked with the disease pyridoxine-dependent seizures. While it is well established that lysine metabolism takes place in the mitochondrial matrix, evidence for the mitochondrial localization of antiquitin has been lacking. In the present study, the subcellular localization of antiquitin was investigated using human embryonic kidney HEK293 cells. Three different approaches were used. First, confocal microscopic analysis was carried out on cells transiently transfected with fusion constructs containing enhanced green fluorescent protein with different lengths of antiquitin based on the different potential start codons of translation. Second, immunofluorescence staining was used to detect the localization of antiquitin directly in the cells. Third, subcellular fractionation was carried out and the individual fraction was analyzed for the presence of antiquitin by Western blot and flow cytometric analyses. All the results showed that antiquitin was present not only in the cytosol but also in the mitochondria.
Wong
Judy Wei-Yan
JW
Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Chan
Chi-Lung
CL
Tang
Wai-Kwan
WK
Cheng
Christopher Hon-Ki
CH
Fong
Wing-Ping
WP
D000444:Aldehyde Dehydrogenase / Q000378:metabolism*; D015153:Blotting, Western; D002460:Cell Line; D002469:Cell Separation; D003600:Cytosol / Q000201:enzymology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000201:enzymology*; D014162:Transfection
C089507:ALDH7A1 protein, human; D000444:Aldehyde Dehydrogenase