Multiphasic denaturation of the λ repressor by urea and its implications for the repressor structure

Urea denaturation of the λ repressor has been studied by fluorescence and circular dichroic spectroscopies. Three phases of denaturation could be detected which we have assigned to part of the C-terminal domain, N-terminal domain and subunit dissociation coupled with further denaturation of the rest of the C-terminal domain at increasing urea concentrations. Acrylamide quenching suggests that at least one of the three tryptophan residues of the λ repressor is in a different environment and its emission maximum is considerably blue-shifted. The transition in low urea concentration (midpoint approximately 2 M) affects the environment of this tryptophan residue, which is located in the C-terminal domain. Removal of the hinge and the N-terminal domain shifts this transition towards even lower urea concentrations, indicating the presence of interaction between hinge on N-terminal and C-terminal domains in the intact repressor

A Parkinson's disease gene regulatory network identifies the signaling protein RGS2 as a modulator of LRRK2 activity and neuronal toxicity

Mutations in LRRK2 are one of the primary genetic causes of Parkinson's disease (PD). LRRK2 contains a kinase and a GTPase domain, and familial PD mutations affect both enzymatic activities. However, the signaling mechanisms regulating LRRK2 and the pathogenic effects of familial mutations remain unknown. Identifying the signaling proteins that regulate LRRK2 function and toxicity remains a critical goal for the development of effective therapeutic strategies. In this study, we apply systems biology tools to human PD brain and blood transcriptomes to reverse-engineer a LRRK2-centered gene regulatory network. This network identifies several putative master regulators of LRRK2 function. In particular, the signaling gene RGS2, which encodes for a GTPase-activating protein (GAP), is a key regulatory hub connecting the familial PD-associated genes DJ-1 and PINK1 with LRRK2 in the network. RGS2 expression levels are reduced in the striata of LRRK2 and sporadic PD patients. We identify RGS2 as a novel interacting partner of LRRK2 in vivo. RGS2 regulates both the GTPase and kinase activities of LRRK2. We show in mammalian neurons that RGS2 regulates LRRK2 function in the control of neuronal process length. RGS2 is also protective against neuronal toxicity of the most prevalent mutation in LRRK2, G2019S. We find that RGS2 regulates LRRK2 function and neuronal toxicity through its effects on kinase activity and independently of GTPase activity, which reveals a novel mode of action for GAP proteins. This work identifies RGS2 as a promising target for interfering with neurodegeneration due to LRRK2 mutations in PD patient

A Parkinson's disease gene regulatory network identifies the signaling protein RGS2 as a modulator of LRRK2 activity and neuronal toxicity

Mutations in LRRK2 are one of the primary genetic causes of Parkinson's disease (PD). LRRK2 contains a kinase and a GTPase domain, and familial PD mutations affect both enzymatic activities. However, the signaling mechanisms regulating LRRK2 and the pathogenic effects of familial mutations remain unknown. Identifying the signaling proteins that regulate LRRK2 function and toxicity remains a critical goal for the development of effective therapeutic strategies. In this study, we apply systems biology tools to human PD brain and blood transcriptomes to reverse-engineer a LRRK2-centered gene regulatory network. This network identifies several putative master regulators of LRRK2 function. In particular, the signaling gene RGS2, which encodes for a GTPase-activating protein (GAP), is a key regulatory hub connecting the familial PD-associated genes DJ-1 and PINK1 with LRRK2 in the network. RGS2 expression levels are reduced in the striata of LRRK2 and sporadic PD patients. We identify RGS2 as a novel interacting partner of LRRK2 in vivo. RGS2 regulates both the GTPase and kinase activities of LRRK2. We show in mammalian neurons that RGS2 regulates LRRK2 function in the control of neuronal process length. RGS2 is also protective against neuronal toxicity of the most prevalent mutation in LRRK2, G2019S. We find that RGS2 regulates LRRK2 function and neuronal toxicity through its effects on kinase activity and independently of GTPase activity, which reveals a novel mode of action for GAP proteins. This work identifies RGS2 as a promising target for interfering with neurodegeneration due to LRRK2 mutations in PD patients

Protection against peroxynitrite by pseudoperoxidase from Leishmania major

Heme proteinssharetheabilitytodetoxifyreactivenitrogenintermediates(NOandperoxynitrite).But, to date,noheme-containingenzymaticdefenseagainsttoxicreactivenitrogenintermediateshasbeen discoveredin Leishmania species.Wehavecloned,expressed,andcharacterizedapseudoperoxidase from Leishmaniamajor (LmPP) thatiscapableofdetoxifyingperoxynitrite(ONOO�). Optical,EPR,and resonanceRamanspectralstudiesdemonstratethatONOO� can rapidlyconvertthesix-coordinate ferric low-spintoaferrichigh-spinformatneutralpH.Westernblottingandimmunofluorescence studieswithanti-LmPPantibodyshowthatthemature enzymeislocatedattheplasmamembraneof amastigotes andisexpressedeightfoldhigherinamastigotes comparedtopromastigotes.Moreover,to further investigateitsexactphysiologicalrolein Leishmania, we havecreatedLmPP-knockoutmutantsby gene replacementin L. major strains. IC50 valuesforexogenouslyaddedH2O2 or 3-morpholinosydnonimine (SIN1)showthatdeletionofLmPPin L. major renders thecellmoresusceptibletoSIN1.Thenullmutantcells exhibitamarkeddecreaseinvirulenceoninfectionwith activatedmacrophagesaswellasinoculationinto BALB/c mice.Collectively,thesedataprovidestrong evidencethatLmPPplaysanimportantroleinthe enzymaticdefenseagainstONOO� within macrophages

Not Available

TECHNOLOGIES ADOPTED & POPULARIZED FOR INCOME ENHANCMENT THROUGH PARTICIPATORY MODE IN ANDAMAN & NICOBAR ISLANDSNot Availabl

Similar Patterns of Mitochondrial Vulnerability and Rescue Induced by Genetic Modification of alfa-Synuclein, Parkin, and DJ-1 in Caenorhabditis elegans

National Institutes of Health Grants NS41786 and AG/NS17485 and United States Army Medical Research Command Grant 17-01-1-078

Redox-Induced Interconversion and Ligand-Centered Hemilability in Ni^II Complexes of Redox-Noninnocent Azo-Aromatic Pincers

A series of nickel­(II) complexes, namely, [Ni^II(L^a–c)₂Cl₂] (<b>1a</b>–<b>c</b>), [Ni^II(L^a,b)₃]­(X)₂ {([<b>2a</b>]­(X)₂, [<b>2b</b>]­(X)₂) (X = ClO₄, I₃)}, [Ni^II(L^c)₂­(OH₂)₂]­(ClO₄)₂ ([<b>3</b>]­(ClO₄)₂) and [Ni^II{(L^a,b)^·–}₂] (<b>4a</b>, <b>4b</b>) featuring the redox-active tridentate azo-aromatic pincer ligand 2-(arylazo)-1,10-phenanthroline (<b>L</b>) were synthesized. The coordinated azo-aromatic ligand showed reversible hemilability depending on its formal oxidation state. On the one hand, in its native state, the unreduced ligand <b>L</b> shows bidentate coordination; the 1,10-phenanthroline moiety binds the central Ni­(II) atom in a bidentate fashion, while the azo-chromophore remains pendent. On the other hand, the one-electron reduced ligand [<b>L</b>]^·– binds the nickel­(II) atom in a tridentate fashion. In complexes <b>1</b>, [<b>2</b>]²⁺, and [<b>3</b>]²⁺, the 1,10-phenanthroline moiety of the neutral unreduced azo-aromatic ligand <b>L</b> binds the central nickel­(II) atom in a bidentate fashion, while the azo-chromophore remains pendent. The complex <b>4</b> is a singlet diradical species, where two monoanionic azo-anion radical ligands [<b>L</b>]^·– are bound to the central nickel­(II) center in a tridentate fashion. Redox-induced reversible hemilability of the coordinated azo-aromatic ligand <b>L</b> was revealed from the interconversion of the synthesized complexes upon reduction and oxidation. Complex <b>1</b> upon reduction transformed to complex <b>4</b> with the loss of two chlorido ligands, whereas the complex <b>4</b> upon oxidation in the presence of excess chloride (LiCl) source transformed back to <b>1</b>. Similarly, the complexes [<b>2</b>]²⁺ and <b>4</b> were also found to be interconvertible upon reduction and oxidation, respectively. Thorough experimental and density functional theory studies were performed to unveil the electronic structures of the synthesized complexes, and attempt was made to understand the redox-induced hemilability of the coordinated azo-aromatic ligand <b>L</b>

Lipid-based nutrient supplements for pregnant women reduce newborn stunting in a cluster-randomized controlled effectiveness trial in Bangladesh.

BackgroundMaternal undernutrition and newborn stunting [birth length-for-age z score (LAZ) &lt;-2] are common in Bangladesh.ObjectiveThe objective was to evaluate the effect of lipid-based nutrient supplements for pregnant and lactating women (LNS-PLs) on birth outcomes.DesignWe conducted a cluster-randomized effectiveness trial (the Rang-Din Nutrition Study) within a community health program in rural Bangladesh. We enrolled 4011 pregnant women at ≤20 gestational weeks; 48 clusters received iron and folic acid (IFA; 60 mg Fe + 400 μg folic acid) and 16 clusters received LNS-PLs (20 g/d, 118 kcal) containing essential fatty acids and 22 vitamins and minerals. Both of the supplements were intended for daily consumption until delivery. Primary outcomes were birth weight and length.ResultsInfants in the LNS-PL group had higher birth weights (2629 ± 408 compared with 2588 ± 413 g; P = 0.007), weight-for-age z scores (-1.48 ± 1.01 compared with -1.59 ± 1.02; P = 0.006), head-circumference-for-age z scores (HCZs; -1.26 ± 1.08 compared with -1.34 ± 1.12; P = 0.028), and body mass index z scores (-1.57 ± 1.05 compared with -1.66 ± 1.03; P = 0.005) than those in the IFA group; in adjusted models, the differences in length (47.6 ± 0.07 compared with 47.4 ± 0.04 cm; P = 0.043) and LAZ (-1.15 ± 0.04 compared with -1.24 ± 0.02; P = 0.035) were also significant. LNS-PLs reduced the risk of newborn stunting (18.7% compared with 22.6%; RR: 0.83; 95% CI: 0.71, 0.97) and small head size (HCZ &lt;-2) (20.7% compared with 24.9%; RR: 0.85; 95% CI: 0.73, 0.98). The effects of LNS-PL on newborn stunting were greatest in infants born before a 10-wk interruption in LNS-PL distribution (n = 1301; 15.7% compared with 23.6%; adjusted RR: 0.69; 95% CI: 0.53, 0.89) and in infants born to women ≤24 y of age or with household food insecurity.ConclusionPrenatal lipid-based nutrient supplements can improve birth outcomes in Bangladeshi women, especially those at higher risk of fetal growth restriction. This trial was registered at clinicaltrials.gov as NCT01715038