Facile transfer of [2Fe-2S] clusters from the diabetes drug target mitoNEET to an apo-acceptor protein
| Autor: | Mark L. Paddock, José N. Onuchic, Sagi Tamir, Zvi Ioav Cabantchik, Andrea R. Conlan, Dorit Michaeli, Ron Mittler, John A. Zuris, Patricia A. Jennings, Maya Shvartsman, Rachel Nechushtai, Yael Harir |
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| Rok vydání: | 2011 |
| Předmět: |
Iron-Sulfur Proteins
medicine.drug_class Stereochemistry Iron Mutant Mitochondrion Models Biological Permeability Mitochondrial Proteins Structure-Activity Relationship 03 medical and health sciences 0302 clinical medicine medicine Humans Hypoglycemic Agents Structure–activity relationship Histidine Thiazolidinedione Ferredoxin 030304 developmental biology 0303 health sciences Multidisciplinary Pioglitazone Chemistry Biological Sciences Acceptor Mitochondria HEK293 Cells Ferredoxins Mutant Proteins Thiazolidinediones Oxidation-Reduction 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Proceedings of the National Academy of Sciences. 108:13047-13052 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | MitoNEET (mNT) is an outer mitochondrial membrane target of the thiazolidinedione diabetes drugs with a unique fold and a labile [2Fe-2S] cluster. The rare 1-His and 3-Cys coordination of mNT’s [2Fe-2S] leads to cluster lability that is strongly dependent on the presence of the single histidine ligand (His87). These properties of mNT are similar to known [2Fe-2S] shuttle proteins. Here we investigated whether mNT is capable of cluster transfer to acceptor protein(s). Facile [2Fe-2S] cluster transfer is observed between oxidized mNT and apo-ferredoxin (a-Fd) using UV-VIS spectroscopy and native-PAGE, as well as with a mitochondrial iron detection assay in cells. The transfer is unidirectional, proceeds to completion, and occurs with a second-order-reaction rate that is comparable to known iron-sulfur transfer proteins. Mutagenesis of His87 with Cys (H87C) inhibits transfer of the [2Fe-2S] clusters to a-Fd. This inhibition is beyond that expected from increased cluster kinetic stability, as the equivalently stable Lys55 to Glu (K55E) mutation did not inhibit transfer. The H87C mutant also failed to transfer its iron to mitochondria in HEK293 cells. The diabetes drug pioglitazone inhibits iron transfer from WT mNT to mitochondria, indicating that pioglitazone affects a specific property, [2Fe-2S] cluster transfer, in the cellular environment. This finding is interesting in light of the role of iron overload in diabetes. Our findings suggest a likely role for mNT in [2Fe-2S] and/or iron transfer to acceptor proteins and support the idea that pioglitazone’s antidiabetic mode of action may, in part, be to inhibit transfer of mNT’s [2Fe-2S] cluster. |
| Databáze: | OpenAIRE |
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