Cellular localization of alpha-ketoglutarate: glyoxylate carboligase in rat tissues.
Biochim Biophys Acta
; 499(3): 321-8, 1977 Oct 25.
Article
in En
| MEDLINE
| ID: mdl-911888
ABSTRACT
alpha-Ketoglutarate glyoxylate carboligase activity has been reported by other laboratories to be present in mitochondria and in the cytosol of mammalian tissues; the mitochondrial activity is associated with the alpha-ketoglutarate decarboxylase moiety of the alpha-ketoglutarate dehydrogenase complex. The cellular distribution of the carboligase has been re-examined here using marker enzymes of known localization in order to monitor the composition of subcellular fractions prepared by differential centrifugation. Carboligase activity paralleled the activity of the mitochondrial matrix enzyme citrate synthase in subcellular fractions prepared from rat liver, heart and brain as well as from rabbit liver. Whole rat liver mitochondria upon lysis released both carboligase and citrate synthase. The activity patterns of several other extramitochondrial marker enzymes differed significantly from that of carboligase in rat liver. In addition, the distribution pattern of carboligase was similar to that of alpha-ketoglutarate decarboxylase and of alpha-ketoglutarate dehydrogenase complex. The data indicate that alpha-ketoglutarate glyoxylate carboligase activity is located exclusively within the mitochondria of the rat and rabbit tissues investigated. There is no evidence for a cytosolic form of the enzyme. Thus the report from other laboratory that the molecular etiology of the human genetic disorder hyperoxaluria type I is a deficiency of cytosolic carboligase must be questioned.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oxo-Acid-Lyases
/
Liver
Limits:
Animals
Language:
En
Journal:
Biochim Biophys Acta
Year:
1977
Document type:
Article
Publication country:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS