The dynamic spore

Driks, Adam

doi:10.1073/pnas.0730807100

Cited by 104 publications

(110 citation statements)

References 36 publications

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“…More recent studies have shown that enzymic activity is associated with a specific coat component (Enguita et al, 2002(Enguita et al, , 2003Martins et al, 2002) and that the coat surface presents peculiar structures (ridges) that seem to be formed when the spore volume decreases (during sporulation) and to disappear when the spore swells (during germination) (Chada et al, 2003). These findings suggest that the coat is a dynamic structure that may sense the external environment through active enzymes present on its surface and adapt to changes in the spore volume by expanding and contracting in response to dehydration and rehydration occurring during the B. subtilis life cycle (Driks, 2003).…”

Section: Introductionmentioning

confidence: 82%

GerE-independent expression of cotH leads to CotC accumulation in the mother cell compartment during Bacillus subtilis sporulation

et al. 2004

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Section: Introductionmentioning

confidence: 82%

GerE-independent expression of cotH leads to CotC accumulation in the mother cell compartment during Bacillus subtilis sporulation

et al. 2004

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“…The mature spore is not static. It expands and contracts in response to changes in relative humidity [4,8,9]. Although ridges are present in spores of many if not most species [2,[15][16][17] of the family Bacillaceae, these ridges are very poorly understood; we do not understand the forces guiding their formation, how their topography is influenced by the coat's material properties or their biological function, if any.…”

Section: Introductionmentioning

confidence: 99%

“…The coat protects the genetic material while permitting the diffusion of water and small molecules to the spore interior. Paradoxically, the coat must be chemically resilient and physically tough [5][6][7] but still possess significant mechanical flexibility [4,8,9]. During germination, the coat must be broken apart so that it can be rapidly shed [10].…”

Section: Introductionmentioning

confidence: 99%

Physical basis for the adaptive flexibility of Bacillus spore coats

Şahin

Yong

Driks

et al. 2012

J. R. Soc. Interface.

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Bacillus spores are highly resistant dormant cells formed in response to starvation. The spore is surrounded by a structurally complex protein shell, the coat, which protects the genetic material. In spite of its dormancy, once nutrient is available (or an appropriate physical stimulus is provided) the spore is able to resume metabolic activity and return to vegetative growth, a process requiring the coat to be shed. Spores dynamically expand and contract in response to humidity, demanding that the coat be flexible. Despite the coat's critical biological functions, essentially nothing is known about the design principles that allow the coat to be tough but also flexible and, when metabolic activity resumes, to be efficiently shed. Here, we investigated the hypothesis that these apparently incompatible characteristics derive from an adaptive mechanical response of the coat. We generated a mechanical model predicting the emergence and dynamics of the folding patterns uniformly seen in Bacillus spore coats. According to this model, spores carefully harness mechanical instabilities to fold into a wrinkled pattern during sporulation. Owing to the inherent nonlinearity in their formation, these wrinkles persist during dormancy and allow the spore to accommodate changes in volume without compromising structural and biochemical integrity. This characteristic of the spore and its coat may inspire design of adaptive materials.

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“…The mature spores of B. subtilis have three distinct structures, the core, cortex and coat, which can be observed using transmission electron microscopy (Aronson & Fitz-James, 1976). The core is the central part of the spore and is surrounded by a membrane and a thick peptidoglycan layer called the cortex (Driks, 2003). The coat is the outermost layer and is composed of many proteins arranged in an electron-dense, thick outer layer and a thinner, lamellar inner layer (Driks, 1999).…”

Section: Introductionmentioning

confidence: 99%

Bacillus subtilis spoVIF (yjcC) gene, involved in coat assembly and spore resistance

et al. 2003

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In systematic screening four sporulation-specific genes, yjcA, yjcB, yjcZ and yjcC, of unknown function were found in Bacillus subtilis. These genes are located just upstream of the cotVWXYZ gene cluster oriented in the opposite direction. Northern blot analysis showed that yjcA was transcribed by the SigE RNA polymerase beginning 2 h (t 2 ) after the onset of sporulation, and yjcB, yjcZ and yjcC were transcribed by the SigK RNA polymerase beginning at t 4 of sporulation. The transcription of yjcZ was dependent on SigK and GerE. The consensus sequences of the appropriate sigma factors were found upstream of each gene. There were putative GerE-binding sites upstream of yjcZ. Insertional inactivation of the yjcC gene resulted in a reduction in resistance of the mutant spores to lysozyme and heat. Transmission electron microscopic examination of yjcC spores revealed a defect of sporulation at stage VI, resulting in loss of spore coats. These results suggest that YjcC is involved in assembly of spore coat proteins that have roles in lysozyme resistance. It is proposed that yjcC should be renamed as spoVIF.

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The dynamic spore

Cited by 104 publications

References 36 publications

GerE-independent expression of cotH leads to CotC accumulation in the mother cell compartment during Bacillus subtilis sporulation

GerE-independent expression of cotH leads to CotC accumulation in the mother cell compartment during Bacillus subtilis sporulation

Physical basis for the adaptive flexibility of Bacillus spore coats

Bacillus subtilis spoVIF (yjcC) gene, involved in coat assembly and spore resistance

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