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Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria
By targeting mRNA transcripts, non-coding small RNAs (sRNAs) regulate the expression of genes governing a wide range of bacterial functions. In the social myxobacterium Myxococcus xanthus, the sRNA Pxr serves as a gatekeeper of the regulatory pathway controlling the life-cycle transition from vegeta...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10217877/ https://www.ncbi.nlm.nih.gov/pubmed/37239421 http://dx.doi.org/10.3390/genes14051061 |
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author | Cossey, Sarah M. Velicer, Gregory J. Yu, Yuen-Tsu Nicco |
author_facet | Cossey, Sarah M. Velicer, Gregory J. Yu, Yuen-Tsu Nicco |
author_sort | Cossey, Sarah M. |
collection | PubMed |
description | By targeting mRNA transcripts, non-coding small RNAs (sRNAs) regulate the expression of genes governing a wide range of bacterial functions. In the social myxobacterium Myxococcus xanthus, the sRNA Pxr serves as a gatekeeper of the regulatory pathway controlling the life-cycle transition from vegetative growth to multicellular fruiting body development. When nutrients are abundant, Pxr prevents the initiation of the developmental program, but Pxr-mediated inhibition is alleviated when cells starve. To identify genes essential for Pxr function, a developmentally defective strain in which Pxr-mediated blockage of development is constitutively active (strain “OC”) was transposon-mutagenized to identify suppressor mutations that inactivate or bypass Pxr inhibition and thereby restore development. One of the four loci in which a transposon insertion restored development is rnd, encoding the Ribonuclease D protein (RNase D). RNase D is an exonuclease important for tRNA maturation. Here, we show that disruption of rnd abolishes the accumulation of Pxr-S, the product of Pxr processing from a longer precursor form (Pxr-L) and the active inhibitor of development. Additionally, the decrease in Pxr-S caused by rnd disruption was associated with increased accumulation primarily of a longer novel Pxr-specific transcript (Pxr-XL) rather than of Pxr-L. The introduction of a plasmid expressing rnd reverted cells back to OC-like phenotypes in development and Pxr accumulation, indicating that a lack of RNase D alone suppresses the developmental defect of OC. Moreover, an in vitro Pxr-processing assay demonstrated that RNase D processes Pxr-XL into Pxr-L; this implies that overall, Pxr sRNA maturation requires a sequential two-step processing. Collectively, our results indicate that a housekeeping ribonuclease plays a central role in a model form of microbial aggregative development. To our knowledge, this is the first evidence implicating RNase D in sRNA processing. |
format | Online Article Text |
id | pubmed-10217877 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-102178772023-05-27 Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria Cossey, Sarah M. Velicer, Gregory J. Yu, Yuen-Tsu Nicco Genes (Basel) Article By targeting mRNA transcripts, non-coding small RNAs (sRNAs) regulate the expression of genes governing a wide range of bacterial functions. In the social myxobacterium Myxococcus xanthus, the sRNA Pxr serves as a gatekeeper of the regulatory pathway controlling the life-cycle transition from vegetative growth to multicellular fruiting body development. When nutrients are abundant, Pxr prevents the initiation of the developmental program, but Pxr-mediated inhibition is alleviated when cells starve. To identify genes essential for Pxr function, a developmentally defective strain in which Pxr-mediated blockage of development is constitutively active (strain “OC”) was transposon-mutagenized to identify suppressor mutations that inactivate or bypass Pxr inhibition and thereby restore development. One of the four loci in which a transposon insertion restored development is rnd, encoding the Ribonuclease D protein (RNase D). RNase D is an exonuclease important for tRNA maturation. Here, we show that disruption of rnd abolishes the accumulation of Pxr-S, the product of Pxr processing from a longer precursor form (Pxr-L) and the active inhibitor of development. Additionally, the decrease in Pxr-S caused by rnd disruption was associated with increased accumulation primarily of a longer novel Pxr-specific transcript (Pxr-XL) rather than of Pxr-L. The introduction of a plasmid expressing rnd reverted cells back to OC-like phenotypes in development and Pxr accumulation, indicating that a lack of RNase D alone suppresses the developmental defect of OC. Moreover, an in vitro Pxr-processing assay demonstrated that RNase D processes Pxr-XL into Pxr-L; this implies that overall, Pxr sRNA maturation requires a sequential two-step processing. Collectively, our results indicate that a housekeeping ribonuclease plays a central role in a model form of microbial aggregative development. To our knowledge, this is the first evidence implicating RNase D in sRNA processing. MDPI 2023-05-09 /pmc/articles/PMC10217877/ /pubmed/37239421 http://dx.doi.org/10.3390/genes14051061 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Cossey, Sarah M. Velicer, Gregory J. Yu, Yuen-Tsu Nicco Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria |
title | Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria |
title_full | Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria |
title_fullStr | Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria |
title_full_unstemmed | Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria |
title_short | Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria |
title_sort | ribonuclease d processes a small rna regulator of multicellular development in myxobacteria |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10217877/ https://www.ncbi.nlm.nih.gov/pubmed/37239421 http://dx.doi.org/10.3390/genes14051061 |
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