The CRP-family transcriptional regulator DevH regulates expression of heterocyst-specific genes at the later stage of differentiation in the cyanobacterium Anabaena sp. strain PCC 7120

© 2020 John Wiley & Sons Ltd..

Heterocysts are terminally differentiated cells of filamentous cyanobacteria, which are specialized for nitrogen fixation. Because nitrogenase is easily inactivated by oxygen, the intracellular environment of heterocysts is kept microoxic. In heterocysts, the oxygen-evolving photosystem II is inactivated, a heterocyst-specific envelope with an outer polysaccharide layer and an inner glycolipid layer is formed to limit oxygen entry, and oxygen consumption is activated. Heterocyst differentiation, which is accompanied by drastic morphological and physiological changes, requires strictly controlled gene expression systems. Here, we investigated the functions of a CRP-family transcriptional regulator, DevH, in the process of heterocyst differentiation. A devH-knockdown strain, devH-kd, was created by replacing the original promoter with the gifA promoter, which is repressed during heterocyst differentiation. Although devH-kd formed morphologically distinct cells with the heterocyst envelope polysaccharide layer, it was unable to grow diazotrophically. Genes involved in construction of the microoxic environment, such as cox operons and the hgl island, were not upregulated in devH-kd. Moreover, expression of the nif gene cluster was completely abolished. Although CnfR was expressed in devH-kd, the nif gene cluster was not induced even under microoxic conditions. Thus, DevH is necessary for the establishment of a microoxic environment and induction of nitrogenase in heterocysts.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:114

Enthalten in:

Molecular microbiology - 114(2020), 4 vom: 21. Okt., Seite 553-562

Sprache:

Englisch

Beteiligte Personen:

Kurio, Yohei [VerfasserIn]
Koike, Yosuke [VerfasserIn]
Kanesaki, Yu [VerfasserIn]
Watanabe, Satoru [VerfasserIn]
Ehira, Shigeki [VerfasserIn]

Links:

Volltext

Themen:

Anabaena
Bacterial Proteins
DNA-Binding Proteins
DevH protein, Nostoc
EC 1.18.6.1
Heterocyst differentiation
Journal Article
Microoxic intracellular environment
N762921K75
Nitrogen
Nitrogenase
Oxygen
Research Support, Non-U.S. Gov't
S88TT14065
Transcription Factors
Transcriptional regulation

Anmerkungen:

Date Completed 13.07.2021

Date Revised 13.07.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/mmi.14558

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM311430724