University of Dundee

About: University of Dundee is a education organization based out in Dundee, United Kingdom. It is known for research contribution in the topics: Population & Protein kinase A. The organization has 19258 authors who have published 39640 publications receiving 1919433 citations. The organization is also known as: Universitas Dundensis & Dundee University.

Parkin is activated by PINK1-dependent phosphorylation of ubiquitin at Ser65.

Abstract: We have previously reported that the Parkinson's disease-associated kinase PINK1 (PTEN-induced putative kinase 1) is activated by mitochondrial depolarization and stimulates the Parkin E3 ligase by phosphorylating Ser65 within its Ubl (ubiquitin-like) domain. Using phosphoproteomic analysis, we identified a novel ubiquitin phosphopeptide phosphorylated at Ser65 that was enriched 14-fold in HEK (human embryonic kidney)-293 cells overexpressing wild-type PINK1 stimulated with the mitochondrial uncoupling agent CCCP (carbonyl cyanide m-chlorophenylhydrazone), to activate PINK1, compared with cells expressing kinase-inactive PINK1. Ser65 in ubiquitin lies in a similar motif to Ser65 in the Ubl domain of Parkin. Remarkably, PINK1 directly phosphorylates Ser65 of ubiquitin in vitro. We undertook a series of experiments that provide striking evidence that Ser65-phosphorylated ubiquitin (ubiquitinPhospho−Ser65) functions as a critical activator of Parkin. First, we demonstrate that a fragment of Parkin lacking the Ubl domain encompassing Ser65 (ΔUbl-Parkin) is robustly activated by ubiquitinPhospho−Ser65, but not by non-phosphorylated ubiquitin. Secondly, we find that the isolated Parkin Ubl domain phosphorylated at Ser65 (UblPhospho−Ser65) can also activate ΔUbl-Parkin similarly to ubiquitinPhospho−Ser65. Thirdly, we establish that ubiquitinPhospho−Ser65, but not non-phosphorylated ubiquitin or UblPhospho−Ser65, activates full-length wild-type Parkin as well as the non-phosphorylatable S65A Parkin mutant. Fourthly, we provide evidence that optimal activation of full-length Parkin E3 ligase is dependent on PINK1-mediated phosphorylation of both Parkin at Ser65 and ubiquitin at Ser65, since only mutation of both proteins at Ser65 completely abolishes Parkin activation. In conclusion, the findings of the present study reveal that PINK1 controls Parkin E3 ligase activity not only by phosphorylating Parkin at Ser65, but also by phosphorylating ubiquitin at Ser65. We propose that phosphorylation of Parkin at Ser65 serves to prime the E3 ligase enzyme for activation by ubiquitinPhospho−Ser65, suggesting that small molecules that mimic ubiquitinPhospho−Ser65 could hold promise as novel therapies for Parkinson's disease.

ANG mutations segregate with familial and 'sporadic' amyotrophic lateral sclerosis

Abstract: We recently identified angiogenin (ANG) as a candidate susceptibility gene for amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder characterized by adult-onset loss of motor neurons. We now report the finding of seven missense mutations in 15 individuals, of whom four had familial ALS and 11 apparently 'sporadic' ALS. Our findings provide further evidence that variations in hypoxia-inducible genes have an important role in motor neuron degeneration.

The Cap ‘n’ Collar Basic Leucine Zipper Transcription Factor Nrf2 (NF-E2 p45-related Factor 2) Controls Both Constitutive and Inducible Expression of Intestinal Detoxification and Glutathione Biosynthetic Enzymes

Abstract: Northern blotting has shown that mouse small intestine contains relatively large amounts of the nuclear factor-E2 p45-related factor (Nrf) 2 transcription factor but relatively little Nrf1. Regulation of intestinal antioxidant and detoxication enzymes by Nrf2 has been assessed using a mouse line bearing a targeted disruption of the gene encoding this factor. Both Nrf2-/- and Nrf2+/+ mice were fed a control diet or one supplemented with either synthetic cancer chemopreventive agents [butylated hydroxyanisole (BHA), ethoxyquin (EQ), or oltipraz] or phytochemicals [indole-3-carbinol, cafestol and kahweol palmitate, sulforaphane, coumarin (CMRN), or alpha-angelicalactone]. The constitutive level of NAD(P)H:quinone oxidoreductase (NQO) and glutathione S-transferase (GST) enzyme activities in cytosols from small intestine was typically found to be between 30% and 70% lower in samples prepared from Nrf2 mutant mice fed a control diet than in equivalent samples from Nrf2+/+ mice. Most of the chemopreventive agents included in this study induced NQO and GST enzyme activities in the small intestine of Nrf2+/+ mice. Increases of between 2.7- and 6.2-fold were observed in wild-type animals fed diets supplemented with BHA or EQ; increases of about 2-fold were observed with a mixture of cafestol and kahweol palmitate, CMRN, or alpha-angelicalactone; and increases of 1.5-fold were measured with sulforaphane. Immunoblotting confirmed that in the small intestine, the constitutive level of NQO1 is lower in the Nrf2-/- mouse, and it also showed that induction of the oxidoreductase was substantially diminished in the mutant mouse. Immunoblotting class-alpha and class-mu GST showed that constitutive expression of most transferase subunits is also reduced in the small intestine of Nrf2 mutant mice. Significantly, induction of class-alpha and class-mu GST by EQ, BHA, or CMRN is apparent in the gene knockout animal. No consistent change in the constitutive levels of the catalytic heavy subunit of gamma-glutamylcysteinyl synthetase (GCS(h)) was observed in the small intestine of Nrf2-/- mice. However, although the expression of GCS(h) was found to be increased dramatically in the small intestine of Nrf2+/+ mice by dietary BHA or EQ, this induction was essentially abolished in the knockout mice. It is apparent that Nrf2 influences both constitutive and inducible expression of intestinal antioxidant and detoxication proteins in a gene-specific fashion. Immunohistochemistry revealed that induction of NQO1, class-alpha GST, and GCS(h) occurs primarily in epithelial cells of the small intestine. This suggests that the variation in inducibility of NQO1, Gsta1/2, and GCS(h) in the mutant mouse is not attributable to the expression of the enzymes in distinct cell types but rather to differences in the dependency of these genes on Nrf2 for induction.

European clinical guidelines for hyperkinetic disorder-first upgrade

Abstract: BACKGROUND: The validity of clinical guidelines changes over time, because new evidence-based knowledge and experience develop OBJECTIVE: Hence, the European clinical guidelines on hyperkinetic disorder from 1998 had to be evaluated and modified METHOD: Discussions at the European Network for Hyperkinetic Disorders (EUNETHYDIS) and iterative critique of each clinical analysis Guided by evidence-based information and based on evaluation (rather than metaanalysis) of the scientific evidence a group of child psychiatrists and psychologists from several European countries updated the guidelines of 1998 When reliable information is lacking the group gives a clinical consensus when it could be found among themselves RESULTS: The group presents here a set of recommendations for the conceptualization and management of hyperkinetic disorder and attention deficit/hyperactivity disorder (ADHD) CONCLUSION: A general scheme for practice in Europe could be provided, on behalf of the European Society for Child and Adolescent Psychiatry (ESCAP)