• Corpus ID: 555463

Genetic Structure of the Purebred Domestic Dog

@inproceedings{Shen2004GeneticSO,
  title={Genetic Structure of the Purebred Domestic Dog},
  author={Dong Shen and Alberto and Bardelli and Jason A. Sager and Steve Szabo and Janine Ptak and Natalie and Silliman and Brock A. Peters and Michiel S. Heijden and Gregory J Riggins and M. Steven and Powell and Sanford D. Markowitz and W. Beagley Kenneth and Kinzler},
  year={2004}
}

• D. Shen, Alberto, +13 authors Kinzler
• Published 2004
• Biology

PINK1 cDNA and a green fluorescent protein (GFP) reporter plasmid and then stressed with the peptide aldehyde Cbz-leu-leuleucinal (MG-132), which inhibits the proteasome and induces apoptosis via distinct mechanisms, including mitochondrial injury (8). Analysis of TMRM fluorescence in GFPpositive cells revealed that the PINK1 mutation had no significant effect on m under basal conditions (Fig. 3A). However, after stress with MG-132, there was a significant decrease in m from basal levels in cells transfected with G309D PINK1 as compared with wild-type PINK1 (G309D, – 44.1% 8.1; versus wild-type PINK1, 13.0% 13.7; P 0.01; n 8 data sets) (Fig. 3B and fig. S4). We next studied apoptosis of MG-132– stressed SH-SY5Y cells transfected with either wild-type or G309D PINK1 by FACS using annexin V conjugated to the fluorochrome phycoerythrin (annexin V-PE). Annexin V has a high binding affinity for the membrane phospholipid, phosphatidylserine, that is exposed on the surface of apoptotic cells. Consistent with the changes in m after stress, overexpression of wildtype PINK1 but not mutant PINK1 significantly reduced the level of apoptotic cell death induced by MG-132 in GFP-positive cells [vector, 45.4% 5.0; wild-type PINK1, 32.7% 4.0; G309D, 45.8% 5.0; P 0.05; analysis of variance (ANOVA), n 12 data sets] (Fig. 3C and fig. S5). These preliminary findings suggest that wild type PINK1 may protect neurons from stress-induced mitochondrial dysfunction and stress-induced apoptosis and that this effect is abrogated by the G309D mutation. Several lines of evidence suggest that impairment of mitochondrial activity could represent an early critical event in the pathogenesis of sporadic PD (2). Environmental toxins such as 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridin and the pesticide rotenone induce selective death of dopaminergic neurons through inhibition of complex I activity (9, 10). Complex I deficiency and a variety of markers of oxidative stress have been demonstrated in postmortem brains of PD patients (2, 11, 12). In addition, several reports have shown that mitochondrial dysfunction associated with oxidative stress can trigger -synuclein aggregation and accumulation, although the exact mechanisms remain unclear (13). The PINK1 mutations described here occur in the putative serine/threonine kinase domain and thus conceivably could affect kinase activity or substrate recognition. Altered phosphorylation has been reported as a pathogenetic mechanism in other neurodegenerative diseases, including Alzheimer’s disease, tauopathy, and spinocerebellar ataxia (14, 15). The recent demonstration that phosphorylation of -synuclein at serine 129 occurs in Lewy bodies in a variety of brains from humans with synucleinopathy (16) suggests that altered phosphorylation may also play a role in PD. We hypothesize that PINK1 may phosphorylate mitochondrial proteins in response to cellular stress, protecting against mitochondrial dysfunction. PINK1 was originally shown to be upregulated by the tumor suppressor gene PTEN in cancer cells (6 ). In neurons, the PTEN signaling pathway is involved in cell cycle regulation and cell migration and promotes excitotoxin-induced apoptosis in the hippocampus (17 ). However, PINK1 has not been shown to have any effects on PTEN-dependent cell phenotypes (6), and its role in the PTEN pathway therefore requires further investigation.