Transcriptional regulation of development in heterocyst-forming cyanobacteria.
Biochim Biophys Acta Gene Regul Mech
; 1862(7): 673-684, 2019 07.
Article
em En
| MEDLINE
| ID: mdl-29719238
Filamentous, heterocyst-forming cyanobacteria are among the simplest multicellular systems in Nature. In the absence of combined nitrogen, the filaments consist of vegetative cells that fix CO2 through oxygenic photosynthesis and micro-oxic heterocysts specialized for the fixation of N2 in a proportion of about 10 to 1. The development of a heterocyst-containing filament involves differentiation of vegetative cells into heterocysts in a process that requires a distinct gene expression program. Two transcription factors are strictly required, NtcA and HetR. The CRP-family protein NtcA directly activates the expression of multiple genes during heterocyst differentiation - in some cases assisted by coactivators including HetR - and in mature heterocysts, whereas HetR is needed to build high NtcA levels in differentiating heterocysts and directly activates some particular genes. A few other regulators of gene expression participate at specific differentiation steps, and a specific transcription factor, CnfR, activates nif gene expression under the micro-oxic conditions of the heterocyst.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Fatores de Transcrição
/
Cianobactérias
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article