Carvalho S

References (3)

Title : Overcoming insecticide resistance through computational inhibitor design - Correy_2019_Proc.Natl.Acad.Sci.U.S.A_116_21012
Author(s) : Correy GJ , Zaidman D , Harmelin A , Carvalho S , Mabbitt PD , Calaora V , James PJ , Kotze AC , Jackson CJ , London N
Ref : Proc Natl Acad Sci U S A , 116 :21012 , 2019
Abstract : Insecticides allow control of agricultural pests and disease vectors and are vital for global food security and health. The evolution of resistance to insecticides, such as organophosphates (OPs), is a serious and growing concern. OP resistance often involves sequestration or hydrolysis of OPs by carboxylesterases. Inhibiting carboxylesterases could, therefore, restore the effectiveness of OPs for which resistance has evolved. Here, we use covalent virtual screening to produce nano-/picomolar boronic acid inhibitors of the carboxylesterase alphaE7 from the agricultural pest Lucilia cuprina as well as a common Gly137Asp alphaE7 mutant that confers OP resistance. These inhibitors, with high selectivity against human acetylcholinesterase and low to no toxicity in human cells and in mice, act synergistically with the OPs diazinon and malathion to reduce the amount of OP required to kill L. cuprina by up to 16-fold and abolish resistance. The compounds exhibit broad utility in significantly potentiating another OP, chlorpyrifos, against the common pest, the peach-potato aphid (Myzus persicae). These compounds represent a solution to OP resistance as well as to environmental concerns regarding overuse of OPs, allowing significant reduction of use without compromising efficacy.
ESTHER : Correy_2019_Proc.Natl.Acad.Sci.U.S.A_116_21012
PubMedSearch : Correy_2019_Proc.Natl.Acad.Sci.U.S.A_116_21012
PubMedID: 31575743
Gene_locus related to this paper: luccu-E3aest7

Title : Protein CutA undergoes an unusual transfer into the secretory pathway and affects the folding, oligomerization, and secretion of acetylcholinesterase - Liang_2009_J.Biol.Chem_284_5195
Author(s) : Liang D , Nunes-Tavares N , Xie HQ , Carvalho S , Bon S , Massoulie J
Ref : Journal of Biological Chemistry , 284 :5195 , 2009
Abstract : The mammalian protein CutA was first discovered in a search for the membrane anchor of mammalian brain acetylcholinesterase (AChE). It was co-purified with AChE, but it is distinct from the real transmembrane anchor protein, PRiMA. CutA is a ubiquitous trimeric protein, homologous to the bacterial CutA1 protein that belongs to an operon involved in resistance to divalent ions ("copper tolerance A"). The function of this protein in plants and animals is unknown, and several hypotheses concerning its subcellular localization have been proposed. We analyzed the expression and the subcellular localization of mouse CutA variants, starting at three in-frame ATG codons, in transfected COS cells. We show that CutA produces 20-kDa (H) and 15-kDa (L) components. The H component is transferred into the secretory pathway and secreted, without cleavage of a signal peptide, whereas the L component is mostly cytosolic. We show that expression of the longer CutA variant reduces the level of AChE, that this effect depends on the AChE C-terminal peptides, and probably results from misfolding. Surprisingly, CutA increased the secretion of a mutant possessing a KDEL motif at its C terminus; it also increased the formation of AChE homotetramers. We found no evidence for a direct interaction between CutA and AChE. The longer CutA variant seems to affect the processing and trafficking of secretory proteins, whereas the shorter one may have a distinct function in the cytoplasm.
ESTHER : Liang_2009_J.Biol.Chem_284_5195
PubMedSearch : Liang_2009_J.Biol.Chem_284_5195
PubMedID: 19049969

Title : Acetylcholinesterase associates differently with its anchoring proteins ColQ and PRiMA - Noureddine_2008_J.Biol.Chem_283_20722
Author(s) : Noureddine H , Carvalho S , Schmitt C , Massoulie J , Bon S
Ref : Journal of Biological Chemistry , 283 :20722 , 2008
Abstract : Acetylcholinesterase tetramers are inserted in the basal lamina of neuromuscular junctions or anchored in cell membranes through the interaction of four C-terminal t peptides with proline-rich attachment domains (PRADs) of cholinesterase-associated collagen Q (ColQ) or of the transmembrane protein PRiMA (proline-rich membrane anchor). ColQ and PRiMA differ in the length of their proline-rich motifs (10 and 15 residues, respectively). ColQ has two cysteines upstream of the PRAD, which are disulfide-linked to two AChE(T) subunits ("heavy" dimer), and the other two subunits are disulfide-linked together ("light" dimer). In contrast, PRiMA has four cysteines upstream of the PRAD. We examined whether these cysteines could be linked to AChE(T) subunits in complexes formed with PRiMA in transfected COS cells and in the mammalian brain. For comparison, we studied complexes formed with N-terminal fragments of ColQ, N-terminal fragments of PRiMA, and chimeras in which the upstream regions containing the cysteines were exchanged. We also compared the effect of mutations in the t peptides on their association with the two PRADs. We report that the two PRADs differ in their interaction with AChE(T) subunits; in complexes formed with the PRAD of PRiMA, we observed light dimers, but very few heavy dimers, even though such dimers were formed with the PQ chimera in which the N-terminal region of PRiMA was associated with the PRAD of ColQ. Complexes with PQ or with PRiMA contained heavy components, which migrated abnormally in SDS-PAGE but probably resulted from disulfide bonding of four AChE(T) subunits with the four upstream cysteines of the associated protein.
ESTHER : Noureddine_2008_J.Biol.Chem_283_20722
PubMedSearch : Noureddine_2008_J.Biol.Chem_283_20722
PubMedID: 18511416