Immunological detection of the mitochondrial F1-ATPase alpha subunit in the matrix of rat liver peroxisomes. A protein involved in organelle biogenesis?
Rat liver peroxisomes contain in their matrix the alpha-subunit of the mitochondrial F1-ATPase complex. The identification of this protein in liver peroxisomes has been achieved by immunoelectron microscopy and subcellular fractionation. No beta-subunit of the mitochondrial F1-ATPase complex was detected in the peroxisomal fractions obtained in sucrose gradients or in Nycodenz pelletted peroxisomes. The consensus peroxisomal targeting sequence (Ala-Lys-Leu) is found at the carboxy terminus of the mature alpha-subunit from bovine heart and rat liver mitochondria. Due to the dual subcellular localization of the alpha-subunit and to the structural homologies that exist between this protein and molecular chaperones [(1990) Biol. Chem. 265, 7713-7716] it is suggested that the protein should perform another functional role(s) in both organelles, plus to its characteristic involvement in the regulation of mitochondrial ATPase activity.
Cuezva
J M
JM
Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain.
Santarén
J F
JF
González
P
P
Valcarce
C
C
Luis
A M
AM
Izquierdo
J M
JM
D000818:Animals; D002499:Centrifugation, Density Gradient; D005333:Fetus / Q000201:enzymology; D008099:Liver / Q000196:embryology; D008830:Microbodies / Q000201:enzymology* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D008930:Mitochondria, Liver / Q000201:enzymology* / Q000648:ultrastructure; D006180:Proton-Translocating ATPases / Q000032:analysis / Q000502:physiology*; D051381:Rats; D013347:Subcellular Fractions / Q000201:enzymology
D006180:Proton-Translocating ATPases