Characterization of mitochondrial NADH dehydrogenase 1α subcomplex 10 variants in cardiac muscles from normal Wistar rats and spontaneously hypertensive rats: Implications in the pathogenesis of hypertension.

Mitochondrial dysfunction has been increasingly associated with the development of cardiovascular diseases, including hypertension and cardiac hypertrophy. In the present study, NADH dehydrogenase 1α subcomplex 10 (Ndufa10) was characterized from the left ventricular muscles of spontaneously hypertensive rats (SHRs) and normal Wistar Kyoto (WKY) rats. Western blot analysis demonstrated that there was a shift in the molecular weight (MW) and in the isoelectric point (pI) of the Ndufa10 protein from SHRs and WKY rats. Mass spectrometric analysis revealed that the replacement of an aspartate residue with asparagine at amino acid position 120 was the biochemical difference between the two Ndufa10 isoforms. Further analysis using the bacterially expressed proteins Ndufa10‑120N (WKY) and Ndufa10‑120D (SHR) revealed that the shift in the pI and MW of the two Ndufa10 isoforms was solely caused by the amino acid mutation, and not by post‑translational modifications. Since deficiencies of the mitochondrial complex I are the most common defects in the oxidative phosphorylation system, further studies are required to study the difference between the activities of the two Ndufa10 variants, and their role in the pathogenesis of hypertension.