Discovery of a novel type IIb RelBE toxin-antitoxin system in Mycobacterium tuberculosis defined by co-regulation with an antisense RNA.
Mol Microbiol
; 117(6): 1419-1433, 2022 06.
Article
en En
| MEDLINE
| ID: mdl-35526138
ABSTRACT
Toxin-antitoxin loci regulate adaptive responses to stresses associated with the host environment and drug exposure. Phylogenomic studies have shown that Mycobacterium tuberculosis encodes a naturally expanded type II toxin-antitoxin system, including ParDE/RelBE superfamily members. Type II toxins are presumably regulated exclusively through protein-protein interactions with type II antitoxins. However, experimental observations in M. tuberculosis indicated that additional control mechanisms regulate RelBE2 type II loci under host-associated stress conditions. Herein, we describe for the first time a novel antisense RNA, termed asRelE2, that co-regulates RelE2 production via targeted processing by the Mtb RNase III, Rnc. We find that convergent expression of this coding-antisense hybrid TA locus, relBE2-asrelE2, is controlled in a cAMP-dependent manner by the essential cAMP receptor protein transcription factor, Crp, in response to the host-associated stresses of low pH and nutrient limitation. Ex vivo survival studies with relE2 and asrelE2 knockout strains showed that RelE2 contributes to Mtb survival in activated macrophages and low pH to nutrient limitation. To our knowledge, this is the first report of a novel tripartite type IIb TA loci and antisense post-transcriptional regulation of a type II TA loci.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
2_ODS3
/
3_ND
Problema de salud:
2_enfermedades_transmissibles
/
3_neglected_diseases
/
3_tuberculosis
Asunto principal:
Toxinas Bacterianas
/
Antitoxinas
/
Sistemas Toxina-Antitoxina
/
Mycobacterium tuberculosis
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos