Novel Mitochondrial Creatine Transport Activity
| Autor: | Else Zanolla, Ove Eriksson, Olliver Speer, Theo Wallimann, Bernd Walzel, Paolo Bernardi |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
0303 health sciences
030302 biochemistry & molecular biology Kidney metabolism Creatine transport Cell Biology Biology Mitochondrion Creatine Biochemistry 3. Good health Phosphocreatine 03 medical and health sciences chemistry.chemical_compound chemistry biology.protein Creatine kinase Inner mitochondrial membrane Molecular Biology Heart metabolism 030304 developmental biology |
| Zdroj: | Journal of Biological Chemistry. 277:37503-37511 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m201168200 |
| Popis: | Immunoblotting of isolated mitochondria from rat heart, liver, kidney, and brain with antibodies made against N- and C-terminal peptide sequences of the creatine transporter, together with in situ immunofluorescence staining and immunogold electron microscopy of adult rat myocardium, revealed two highly related polypeptides with molecular masses of ∼70 and ∼55 kDa in mitochondria. These polypeptides were localized by immunoblotting of inner and outer mitochondrial membrane fractions, as well as by immunogold labeling in the mitochondrial inner membrane. In addition, a novel creatine uptake via a mitochondrial creatine transport activity was demonstrated by [14C]creatine uptake studies with isolated mitochondria from rat liver, heart, and kidney showing a saturable low affinity creatine transporter, which was largely inhibited in a concentration-dependent manner by the sulfhydryl-modifying reagent NEM, as well as by the addition of the above anti-creatine transporter antibodies to partially permeabilized mitochondria. Mitochondrial creatine transport was to a significant part dependent on the energetic state of mitochondria and was inhibited by arginine, and to some extent also by lysine, but not by other creatine analogues and related compounds. The existence of an active creatine uptake mechanism in mitochondria indicates that not only creatine kinase isoenzymes, but also creatine transporters and thus a certain proportion of the creatine kinase substrates, might be subcellularly compartmentalized. Our data suggest that mitochondria, shown here to possess creatine transport activity, may harbor such a creatine/phosphocreatine pool. |
| Databáze: | OpenAIRE |
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