Morphogenetic Pathway of Spore Wall Assembly in Saccharomyces cerevisiae
118
Citation
47
Reference
10
Related Paper
Citation Trend
Abstract:
The Saccharomyces cerevisiae spore is protected from environmental damage by a multilaminar extracellular matrix, the spore wall, which is assembled de novo during spore formation. A set of mutants defective in spore wall assembly were identified in a screen for mutations causing sensitivity of spores to ether vapor. The spore wall defects in 10 of these mutants have been characterized in a variety of cytological and biochemical assays. Many of the individual mutants are defective in the assembly of specific layers within the spore wall, leading to arrests at discrete stages of assembly. The localization of several of these gene products has been determined and distinguishes between proteins that likely are involved directly in spore wall assembly and probable regulatory proteins. The results demonstrate that spore wall construction involves a series of dependent steps and provide the outline of a morphogenetic pathway for assembly of a complex extracellular structure.The extracellular matrix is very well organized at the supramolecular and tissue levels and little is known on the potential role of intrinsic disorder in promoting its organization. We predicted the amount of disorder and identified disordered regions in the human extracellular proteome with established computational tools. The extracellular proteome is significantly enriched in proteins comprising more than 50% of disorder compared to the complete human proteome. The enrichment is mostly due to long disordered regions containing at least 100 consecutive disordered residues. The amount of intrinsic disorder is heterogeneous in the extracellular protein families, with the most disordered being collagens and the small integrin-binding ligand N-linked glycoproteins. Although most domains found in extracellular proteins are structured, the fibronectin III domains contain a variable amount of disordered residues (up to 92%). Binding sites for heparin and integrins are found in disordered sequences of extracellular proteins. Intrinsic disorder is evenly distributed in hubs and ends in the interaction network of extracellular proteins with their extracellular partners. In contrast, extracellular hubs are significantly enriched in disorder in the network of extracellular proteins with their extracellular, membrane and intracellular partners. Disorder could thus provide the structural plasticity required for the hubs to interact with membrane and intracellular proteins. Organization and assembly of the extracellular matrix, development of mineralized tissues and cell–matrix adhesion are the biological processes overrepresented in the most disordered extracellular proteins. Extracellular disorder is associated with binding to growth factors, glycosaminoglycans and integrins at the molecular level.
Proteome
Intrinsically Disordered Proteins
Cite
Citations (57)
A fluorescence microscopic method was developed to directly assess the pathogenic activity of resting spores of Plasmodiophora brassicae. Resting spores were stained with a mixture solution of two fluorochromes, calcofluor white M2R (CFW) and ethidium bromide (EB), and were observed by fluorescence microscopy (phase contrast, UV filter set, oil immersion). All the spores exhibited intense blue fluorescence on the wall layer, and some spores displayed red fluorescence in the cytoplasm. Spores could be distinguished into two groups, spores with a non-fluorescing cytoplasm (blue spores) and spores with a red fluorescing cytoplasm (red spores). The fluorescent staining reaction of the spores was not affected by a staining period of less than 4hr. However, when the concentration of EB solution equally mixed with CFW solution was increased, an increase in the percentage of red spores was observed. Suitable conditions for the differentiation between blue and red fluorescence corresponded to a concentration of 10 to 50μg/ml of the EB solution using 100μg/ml of CFW solution. When spores were heated for 72hr at 40C, 50C or 60C, the percentage of blue spores was constant at 40C, but decreased both at 50C and at 60C with the time of incubation, suggesting that the blue spores are active spores. Disease severity in the plants infected with heat-treated spores was closely related to the percentage of blue spores among the treated spores. This correlation was also observed for the spores stored for different periods of time. The results obtained indicate that the pathogenic activity of the resting spores can be assessed by examining the fluorescent staining reaction of the spores. In this study, the variations in the percentage of blue spores were generally less pronounced than those in the disease severity. This method is rapid, convenient and precise.
Fluorescent staining
Cite
Citations (26)
The objective of this study was to determine the effects of Ca‐dipicolinic acid (CaDPA), cortex‐lytic enzymes (CLEs), the inner membrane (IM) CaDPA channel and coat on spore killing by dodecylamine. Bacillus subtilis spores, wild‐type, CaDPA‐less due to the absence of DPA synthase or the IM CaDPA channel, or lacking CLEs, were dodecylamine‐treated and spore viability and vital staining were all determined. Dodecylamine killed intact wild‐type and CaDPA‐less B. subtilis spores similarly, and also killed intact Clostridiodes difficile spores ± CaDPA, with up to 99% killing with 1 mol l−1 dodecylamine in 4 h at 45°C with spores at ~108 ml−1. Dodecylamine killing of decoated wild type and CLE‐less B. subtilis spores was similar, but ~twofold faster than for intact spores, and much faster for decoated CaDPA‐less spores, with ≥99% killing in 5 min. Propidium iodide stained intact spores ± CaDPA minimally, decoated CaDPA‐replete spores or dodecylamine‐killed CLE‐less spores peripherally, and cores of decoated CaDPA‐less spores and dodecylamine‐killed intact spores with CLEs. The IM of some decoated CaDPA‐less spores was greatly reorganized. Dodecylamine spore killing does not require CaDPA channels, CaDPA or CLEs. The lack of CaDPA in decoated spores allowed strong PI staining of the spore core, indicating loss of these spores IM permeability barrier. This work gives new information on killing bacterial spores by dodecylamine, and how spore IM's relative impermeability is maintained.
Bacterial spore
Dipicolinic acid
Propidium iodide
Cite
Citations (25)
Bacillus (shape)
Cite
Citations (6)
Hg- and Cd-spores of Bacillus megaterium QM B1551 were produced in Schaeffer's medium containing mercuric chloride and cadmium chloride respectively. Metals were added to the medium at 9 hr of incubation (Stage V) to give a final concentration of 50 microM. It was found by electron microscopic and biochemical studies that the coats of both Hg- and Cd-spores were thinner than those of control spores. Of the total Hg and Cd in the spores, 77% of the Hg and 63% of the Cd were detected in the spore coats. Hg- and Cd-spores were less resistant to heat and more sensitive to germinants than control spores. Other properties of Hg- and Cd-spores were similar to those of control spores. These results suggest that the spore coat has some relationship to the heat resistance and germinability of spores.
Cite
Citations (3)
Strain (injury)
Cite
Citations (1)
Abstract Using the techniques of centrifugal elutriation it was demonstrated that during the cell division cycle of the budding yeast Saccharomyces cerevisiae there are stage‐specific fluctuations in the intracellular concentration of adenosine 3′,5′‐cyclic monophosphate (cAMP). Results shown here indicate that the intracellular concentration of cAMP is at its highest during the division cycle, and its lowest immediately prior to and just after cell sepraration. Results also show the extrusion of extracellular cAMP into the medium by Saccharomyces cerevisiae , extracellular cAMP levels being ten to one hundred times higher than intracellular levels. During the cell of Saccharomyces cerevisiae the extracellular level of cAMP does not fluctuate.
Budding
Cite
Citations (37)
To determine how the microbicide ceragenin‐13 (CSA‐13) kills Bacillus subtilis spores prepared on growth or sporulation media, and these spores' properties. Spores made on Luria broth (LB) growth or double‐strength Schaeffer's‐glucose (2xSG) sporulation plates found that spores made on LB plates have coat defects as evidenced by their lower hypochlorite resistance, faster germination with dodecylamine and slower germination with Ca2+‐dipicolinic acid (CaDPA) than 2xSG plate spores. CSA‐13 triggered CaDPA release from spores, an early step in germination, but only well at 70°C and better with spores made on LB than on 2xSG plates. Approximately 90% of spores with elevated levels of SpoVA proteins that form a CaDPA release channel, released CaDPA with CSA‐13 at 70°C, and faster with spores made on LB than 2xSG plates. Levels of CSA‐13 killing of spores made on LB and 2xSG plates were similar to levels of CaDPA release triggered by this agent. CSA‐13 kills bacterial spores, but only at high concentrations and temperatures, and is preceded by CaDPA release. CSA‐13 is not a direct sporicide as reported previously, but most likely germinates spores via activation of spores' CaDPA channel, albeit inefficiently, and then killing the germinated spores.
Dipicolinic acid
Spore germination
Bacillus (shape)
Cite
Citations (4)
ABSTRACT The first ∼10% of spores released from sporangia (early spores) during Bacillus subtilis sporulation were isolated, and their properties were compared to those of the total spores produced from the same culture. The early spores had significantly lower resistance to wet heat and hypochlorite than the total spores but identical resistance to dry heat and UV radiation. Early and total spores also had the same levels of core water, dipicolinic acid, and Ca and germinated similarly with several nutrient germinants. The wet heat resistance of the early spores could be increased to that of total spores if early spores were incubated in conditioned sporulation medium for ∼24 h at 37°C (maturation), and some hypochlorite resistance was also restored. The maturation of early spores took place in pH 8 buffer with Ca 2+ but was blocked by EDTA; maturation was also seen with early spores of strains lacking the CotE protein or the coat-associated transglutaminase, both of which are needed for normal coat structure. Nonetheless, it appears to be most likely that it is changes in coat structure that are responsible for the increased resistance to wet heat and hypochlorite upon early spore maturation.
Dipicolinic acid
Sodium hypochlorite
Heat Resistance
Bacterial spore
Hypochlorite
Bacillus (shape)
Cite
Citations (70)