The Heterocyst-Specific Small RNA NsiR1 Regulates the Commitment to Differentiation in Nostoc
Heterocysts are specialized cells that filamentous cyanobacteria differentiatefor the fixation of atmospheric nitrogen when other nitrogen sources are not available.Heterocyst differentiation at semiregular intervals along the filaments requires complexstructural and metabolic changes that are under th...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/183206 |
| Acceso en línea: | https://hdl.handle.net/11441/183206 https://doi.org/10.1128/spectrum.02274-21 |
| Access Level: | acceso abierto |
| Palabra clave: | Anabaena Regulatory RNAs Cyanobacteria Heterocyst differentiation Small RNAs |
| Sumario: | Heterocysts are specialized cells that filamentous cyanobacteria differentiatefor the fixation of atmospheric nitrogen when other nitrogen sources are not available.Heterocyst differentiation at semiregular intervals along the filaments requires complexstructural and metabolic changes that are under the control of the master transcriptionalregulator HetR. NsiR1 (nitrogen stress-induced RNA 1) is a HetR-dependent noncoding RNAthat is expressed from multiple chromosomal copies, some identical, some slightly divergentin sequence, specifically in heterocysts from very early stages of differentiation. We havepreviously shown that NsiR1 inhibits translation of the overlapping hetF mRNA by anantisense mechanism. Here, we identify alr3234, a hetP-like gene involved in the regula-tion of commitment (point of no return) to heterocyst differentiation, as a target of NsiR1.A strain overexpressing one of the identical copies of NsiR1 commits to heterocyst devel-opment earlier than the wild type. The posttranscriptional regulation exerted by NsiR1 onthe expression of two genes involved in heterocyst differentiation and commitment, hetFand alr3234, adds a new level of complexity to the network of transcriptional regulationand protein-protein interactions that participate in heterocyst differentiation. IMPORTANCE Heterocysts are nitrogen-fixing specialized cells that appear at semiregularintervals along cyanobacterial filaments upon nitrogen starvation. The differentiation andpatterning of heterocysts is a model for the study of cell differentiation in multicellularprokaryotes. The regulation of differentiation, which is only partially understood, includestranscriptional changes, factor diffusion between cells, and protein-protein interactions. Thiswork describes the identification of a novel target for NsiR1, a small RNA (sRNA) encodedin multiple slightly divergent copies, and shows how different copies of “sibling” sRNAs reg-ulate the expression of different targets involved in one of the few examples of a differen-tiation process in prokaryotes. |
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