Dr. Jeremy Rock - Compensatory evolution in NusG improves fitness of drug-resistant Mycobacterium tuberculosis - IPBS-Toulouse, Seminar Room

Jeremy Rock

The Rockefeller University, New York

Compensatory evolution in NusG improves fitness of drug-resistant Mycobacterium tuberculosis

Drug-resistant bacteria are emerging as a global threat, despite frequently being less fit than their drug-susceptible ancestors. Here we sought to define the mechanisms that drive or buffer the fitness cost of rifampicin resistance (RifR) in the bacterial pathogen Mycobacterium tuberculosis (Mtb). Rifampicin inhibits RNA polymerase (RNAP) and is a cornerstone of modern short-course tuberculosis therapy. However, RifR Mtb accounts for one-fifth of all deaths due to drug-resistant bacteria. We took a comparative functional genomics approach to define processes that are differentially vulnerable to CRISPR interference (CRISPRi) inhibition in RifR Mtb. Among other hits, we found that the universally conserved transcription factor NusG is crucial for the fitness of RifR Mtb. In contrast to its role in Escherichia coli, Mtb NusG has an essential RNAP pro-pausing function mediated by distinct contacts with RNAP and the DNA. We find this pro-pausing NusG–RNAP interface to be under positive selection in clinical RifR Mtb isolates. Mutations in the NusG–RNAP interface reduce pro-pausing activity and increase fitness of RifR Mtb. Collectively, these results define excessive RNAP pausing as a molecular mechanism that drives the fitness cost of RifR in Mtb, identify a new mechanism of compensation to overcome this cost, suggest rational approaches to exacerbate the fitness cost, and, more broadly, could inform new therapeutic approaches to develop drug combinations to slow the evolution of RifR in Mtb.

Selected publications

• Eckartt KA, Delbeau M, Munsamy-Govender V, DeJesus MA, Azadian ZA, Reddy AK, Chandanani J, Poulton NC, Quiñones-Garcia S, Bosch B, Landick R, Campbell EA, Rock JM. Compensatory evolution in NusG improves fitness of drug-resistant M. tuberculosis. Nature. 2024 Apr;628(8006):186-194
• Ju X, Li S, Froom R, Wang L, Lilic M, Delbeau M, Campbell EA, Rock JM, Liu S. Incomplete transcripts dominate the Mycobacterium tuberculosis transcriptome. Nature. 2024 Mar;627(8003):424-430
• Poulton NC, DeJesus MA, Munsamy-Govender V, Kanai M, Roberts CG, Azadian ZA, Bosch B, Lin KM, Li S, Rock JM. Beyond antibiotic resistance: The whiB7 transcription factor coordinates an adaptive response to alanine starvation in mycobacteria. Cell Chem Biol. 2024 Apr 18;31(4):669-682.e7
• Wong AI, Beites T, Planck KA, Fieweger RA, Eckartt KA, Li S, Poulton NC, VanderVen BC, Rhee KY, Schnappinger D, Ehrt S, Rock J. Cyclic AMP is a critical mediator of intrinsic drug resistance and fatty acid metabolism in M. tuberculosis. Elife. 2023 Feb 22;12:e81177
• Bosch B, DeJesus MA, Poulton NC, Zhang W, Engelhart CA, Zaveri A, Lavalette S, Ruecker N, Trujillo C, Wallach JB, Li S, Ehrt S, Chait BT, Schnappinger D, Rock JM. Genome-wide gene expression tuning reveals diverse vulnerabilities of M. tuberculosis. Cell. 2021 Aug 19;184(17):4579-4592
• Li S, Poulton NC, Chang JS, Azadian ZA, DeJesus MA, Ruecker N, Zimmerman MD, Eckartt KA, Bosch B, Engelhart CA, Sullivan DF, Gengenbacher M, Dartois VA, Schnappinger D, Rock JM. CRISPRi chemical genetics and comparative genomics identify genes mediating drug potency in Mycobacterium tuberculosis. Nat Microbiol. 2022 Jun;7(6):766-779
• d'Andrea FB, Poulton NC, Froom R, Tam K, Campbell EA, Rock JM. The essential M. tuberculosis Clp protease is functionally asymmetric in vivo. Sci Adv. 2022 May 6;8(18):eabn7943