MmpL3 is the cellular target of the antitubercular pyrrole derivative BM212.
The 1,5-diarylpyrrole derivative BM212 was previously shown to be active against multidrug-resistant clinical isolates and Mycobacterium tuberculosis residing within macrophages as well as against Mycobacterium avium and other atypical mycobacteria. To determine its mechanism of action, we identified the cellular target. Spontaneous Mycobacterium smegmatis, Mycobacterium bovis BCG, and M. tuberculosis H37Rv mutants that were resistant to BM212 were isolated. By the screening of genomic libraries and by whole-genome sequencing, we found that all the characterized mutants showed mutations in the mmpL3 gene, allowing us to conclude that resistance to BM212 maps to the MmpL3 protein, a member of the MmpL (mycobacterial membrane protein, large) family. Susceptibility was unaffected by the efflux pump inhibitors reserpine, carbonylcyanide m-chlorophenylhydrazone, and verapamil. Uptake/efflux experiments with [(14)C]BM212 demonstrated that resistance is not driven by the efflux of BM212. Together, these data strongly suggest that the MmpL3 protein is the cellular target of BM212.
Dipartimento di Genetica e Microbiologia, Universita degli Studi di Pavia, Pavia, Italy.
Valentina
V
La Rosa
Giovanna
G
Poce
Julio Ortiz
JO
Canseco
Silvia
S
Buroni
Maria Rosalia
MR
Pasca
Mariangela
M
Biava
Ravikiran M
RM
Raju
Giulio Cesare
GC
Porretta
Salvatore
S
Alfonso
Claudio
C
Battilocchio
Babak
B
Javid
Flavia
F
Sorrentino
Thomas R
TR
Ioerger
James C
JC
Sacchettini
Fabrizio
F
Manetti
Maurizio
M
Botta
Alessandro
A
De Logu
Eric J
EJ
Rubin
Edda
E
De Rossi
D000818:Animals; D000995:Antitubercular Agents / Q000494:pharmacology*; D002250:Carbon Radioisotopes; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000031:analogs & derivatives / Q000494:pharmacology; D002417:Cattle; D004252:DNA Mutational Analysis; D024901:Drug Resistance, Multiple, Bacterial; D016680:Genome, Bacterial; D015698:Genomic Library; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009165:Mycobacterium Infections, Nontuberculous / Q000188:drug therapy / Q000382:microbiology; D009163:Mycobacterium bovis / Q000187:drug effects / Q000235:genetics*; D020102:Mycobacterium smegmatis / Q000187:drug effects / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D010879:Piperazines / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D012110:Reserpine / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D000995:Antitubercular Agents; D002250:Carbon Radioisotopes; D026901:Membrane Transport Proteins; D010879:Piperazines; D011758:Pyrroles; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D012110:Reserpine; D014700:Verapamil; C115651:BM 212