title: A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes.
abstract: Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5-10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis.
authors.affiliation: New England Biolabs, Division of Genome Biology, Ipswich, Massachusetts, United States of America.
authors.forename: Brendan D
authors.initials: BD
authors.lastname: Galvin
authors.affiliation: New England Biolabs, Division of Genome Biology, Ipswich, Massachusetts, United States of America.
authors.forename: Zhiru
authors.initials: Z
authors.lastname: Li
authors.affiliation: New England Biolabs, Division of Genome Biology, Ipswich, Massachusetts, United States of America.
authors.forename: Estelle
authors.initials: E
authors.lastname: Villemaine
authors.affiliation: New England Biolabs, Division of Genome Biology, Ipswich, Massachusetts, United States of America.
authors.forename: Catherine B
authors.initials: CB
authors.lastname: Poole
authors.affiliation: New England Biolabs, Division of Genome Biology, Ipswich, Massachusetts, United States of America.
authors.forename: Melissa S
authors.initials: MS
authors.lastname: Chapman
authors.affiliation: Northeastern University, Department of Chemistry and Chemical Biology, Boston, Massachusetts, United States of America.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Pollastri
authors.affiliation: Drug Discovery Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Wyatt
authors.affiliation: New England Biolabs, Division of Genome Biology, Ipswich, Massachusetts, United States of America.
authors.forename: Clotilde K S
authors.initials: CK
authors.lastname: Carlow
mesh_terms: D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D017178:Brugia malayi / Q000201:enzymology*; D017173:Caenorhabditis elegans / Q000201:enzymology*; D019295:Computational Biology; D016503:Drug Delivery Systems; D058990:Molecular Targeted Therapy
chemical_list: D000217:Acyltransferases; C050480:glycylpeptide N-tetradecanoyltransferase