(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Protostomia: NE > Ecdysozoa: NE > Panarthropoda: NE > Arthropoda: NE > Mandibulata: NE > Pancrustacea: NE > Hexapoda: NE > Insecta: NE > Dicondylia: NE > Pterygota: NE > Neoptera: NE > Holometabola: NE > Coleoptera: NE > Polyphaga: NE > Cucujiformia: NE > Chrysomeloidea: NE > Chrysomelidae: NE > Chrysomelinae: NE > Doryphorini: NE > Leptinotarsa: NE > Leptinotarsa decemlineata: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MTTTLRVFCLLTTMILIPSSLPNPHRGRHHSPEPHAGAYHISRDPFDPHR DSEEFRRDAPDDGKRDFTRRDSSEDDPLVVQTKRGKVRGVTVTAVTGKKV DAWLGIPYAQKPIGNLRFRHPRPIEKWDGILNTTSQSTSCVQIIDTVFGD FAGSNMWNPNTPLSEDCLFVNVVVPKPRPTNAAVLVWIFGGGFYSGTTTL DIYDHNIIVSEENIILVSMQYRLASLGFLYFGTSDVPGNAGMFDQMMALQ WIKDNIAAFGGNPNNITLFGESAGAVSVSLHLFSPLSRNLFSQAIMQSGT ATAPWAIISREESILRGLRLAEAVGCPHDRSDLSSVIDCLQKKDPIELVD NEWSTLGICEFPFVPVIDGVFLDEHPARSLANKNFKKTNILVGSNSDEGS SFIMYHLTELFRKEENVYVNRQEFLQAVAELNPYVNPISRQAIVFEYTDW LNPDDPVSNRDALDKMVGDYQFTCSVNELAHRYSDTGNNVYMYYYKHRSI ASPWPTWSGAIHGEEINYLFGEPLNPSKSYTPQEVDLSRRMMRYWANFAK TGNPSVNANGVWTPTFWPIHTAFGREYLTLDINSTATGQGPRLKQCAFWK KYLPQLQKMTAELQNTQSSKDCVSLGISISSSWYTLSSFSITLLGIGWKR YQ
References
Title: Characterization of molecular and kinetic properties of two acetylcholinesterases from the Colorado potato beetle, Leptinotarsa decemlineata Yoon KA, Kim JH, Nauen R, Alyokhin A, Clark JM, Lee SH Ref: Pestic Biochem Physiol, 185:105137, 2022 : PubMed
The molecular and biochemical properties of two acetylcholinesterases (LdAChE1 and LdAChE2) from the Colorado potato beetle, Leptinotarsa decemlineata, were investigated in this study. Polyacrylamide gel electrophoresis in conjunction with western blotting with LdAChE1- or LdAChE2-specific antibodies suggested that LdAChE1 exists in a soluble form, whereas LdAChE2 exists in both soluble and amphiphilic forms with a glycophosphatidylinositol anchor. Both LdAChEs exist as homodimers with each monomer connected with a disulfide bond. LdAChE1 was the most highly expressed in the thorax followed by the head, leg, and abdomen, whereas LdAChE2 was the most highly expressed in the head, followed by the thorax, leg, and abdomen. The overall expression levels of LdAChE1, however, were higher than those of LdAChE2 in all examined tissues. Kinetic analysis using recombinant LdAChE1 and LdAChE2 showed that LdAChE2 has a 4.8-fold higher catalytic efficiency toward acetylthiocholine iodide compared to LdAChE1. LdAChE2 was more sensitive to organophosphorus and carbamate insecticides than LdAChE1. The addition of irreversibly phosphorylated LdAChE1 via paraoxon titration significantly reduced LdAChE2 inhibition by insecticides and glycoalkaloids, suggesting a sequestration role of soluble LdAChE1 in the chemical defense against xenobiotics. Taken together, LdAChE2 may be the main enzyme for synaptic transmission, thus serving as a toxicologically more relevant target, whereas the soluble LdAChE1 may function as a bioscavenger.
The Colorado potato beetle (CPB), Leptinotarsa decemlineata is an important economic pest of potato worldwide. Resistance to organophosphates and carbamates in CPB has been associated in some cases to point mutations in the acetylcholinesterase (AChE) gene Ldace2, an orthologue of Drosophila melanogaster Dmace2. In this paper we report cloning and sequencing of Ldace1, an orthologue of Anopheles gambiae Agace1 that was previously unknown in CPB. The Ldace1 coding enzyme contains all residues conserved in a functionally active AChE. Ldace1 is expressed at higher levels (between 2- and 11-fold) than Ldace2 in embryos, in the four larval instars and in adults. Specific interference of Ldace1 by means of dsRNA injection resulted in a reduction of AChE activity to an approximate 50% compared to control, whilst interference of Ldace2 reduced AChE activity to an approximate 85%. Analysis of zymograms of AChE activity after interference indicates that LdAChE1 is the enzyme predominantly responsible for the activity visualised. Interference of Ldace1 in CPB adults caused a significant increase in mortality (43%) as early as three days post-injection (p.i.), suggesting the essential role of Ldace1. Interference of Ldace2 also caused a significant increase in mortality (29%) compared to control, although at seven days p.i. The effect of the interference of Ldace1 on susceptibility to the organophosphate chlorpyrifos points out that LdAChE1 could be a main target for this insecticide. In the light of our results, studies associating resistance in CPB to mutations in Ldace2 should be reviewed, taking into consideration analysis of the Ldace1 gene.
