title: Mutations in the Plasmodium falciparum Cyclic Amine Resistance Locus (PfCARL) Confer Multidrug Resistance.
abstract: Mutations in the Plasmodium falciparum cyclic amine resistance locus (PfCARL) are associated with parasite resistance to the imidazolopiperazines, a potent class of novel antimalarial compounds that display both prophylactic and transmission-blocking activity, in addition to activity against blood-stage parasites. Here, we show that pfcarl encodes a protein, with a predicted molecular weight of 153 kDa, that localizes to the cis-Golgi apparatus of the parasite in both asexual and sexual blood stages. Utilizing clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene introduction of 5 variants (L830V, S1076N/I, V1103L, and I1139K), we demonstrate that mutations in pfcarl are sufficient to generate resistance against the imidazolopiperazines in both asexual and sexual blood-stage parasites. We further determined that the mutant PfCARL protein confers resistance to several structurally unrelated compounds. These data suggest that PfCARL modulates the levels of small-molecule inhibitors that affect Golgi-related processes, such as protein sorting or membrane trafficking, and is therefore an important mechanism of resistance in malaria parasites.
  
  
  
  Several previous in vitro evolution studies have implicated the Plasmodium falciparum cyclic amine resistance locus (PfCARL) as a potential target of imidazolopiperazines, potent antimalarial compounds with broad activity against different parasite life cycle stages. Given that the imidazolopiperazines are currently being tested in clinical trials, understanding their mechanism of resistance and the cellular processes involved will allow more effective clinical usage.
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: LaMonte
authors.affiliation: Novartis Institute for Tropical Diseases, Singapore, Singapore National University of Singapore, Singapore.
authors.forename: Michelle Yi-Xiu
authors.initials: MY
authors.lastname: Lim
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: Wree
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Christin
authors.initials: C
authors.lastname: Reimer
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Nachon
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Corey
authors.affiliation: Novartis Institute for Tropical Diseases, Singapore, Singapore.
authors.forename: Peter
authors.initials: P
authors.lastname: Gedeck
authors.affiliation: Genomics Institute of the Novartis Research Foundation, San Diego, California, USA.
authors.forename: David
authors.initials: D
authors.lastname: Plouffe
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Du
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Nelissa
authors.initials: N
authors.lastname: Figueroa
authors.affiliation: Novartis Institute for Tropical Diseases, Singapore, Singapore.
authors.forename: Bryan
authors.initials: B
authors.lastname: Yeung
authors.affiliation: Novartis Institute for Tropical Diseases, Singapore, Singapore National University of Singapore, Singapore Genomics Institute of the Novartis Research Foundation, San Diego, California, USA pablo.bifani@novartis.com.
authors.forename: Pablo
authors.initials: P
authors.lastname: Bifani
authors.affiliation: Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Winzeler
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D056426:Genetic Loci; D009154:Mutation; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics; D011995:Recombination, Genetic
chemical_list: D000962:Antimalarials; D015800:Protozoan Proteins