The MreB-Like Protein Mbl of Streptomyces coelicolor A3(2) Depends on MreB for Proper Localization and Contributes to Spore Wall Synthesis▿ †
| Autor: | Klas Flärdh, Andrea Heichlinger, Eva-Maria Kleinschnitz, Wolfgang Wohlleben, Annette Latus, Moritz Ammelburg, Iris Maldener, Giinther Muth |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Models
Molecular Molecular Sequence Data Genetics and Molecular Biology Streptomyces coelicolor Microbiology MreB Cell wall chemistry.chemical_compound Amino Acid Sequence Cytoskeleton Molecular Biology Aerial mycelium formation Spores Bacterial biology Escherichia coli Proteins fungi Gene Expression Regulation Bacterial bacterial infections and mycoses biology.organism_classification Fusion protein Cell biology Transport protein Protein Transport chemistry Multigene Family Mutation Peptidoglycan |
| Popis: | Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a Δ mreB Δ mbl double mutant was viable. Δ sco6166 had a wild-type phenotype. Δ mreB , Δ mbl , and Δ mreB Δ mbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δ mbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|