The effect of cycloheximide (actidione) on cell wall synthesis in yeast protoplasts (original) (raw)
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World Journal of Microbiology & Biotechnology, 1992
The optimal conditions for protoplast formation of Candida apicola were by using an enzyme from Arthrobacter sp. in combination with 2-mercaptoethanol. The kinetic data support the two-layered structure model of cell wall for this yeast but the structure of the cell wall depended on the age of cells and culture conditions. To regenerate the protoplasts, the type of osmotic stabilizer was important: sorbitol gave 16 to 30% regeneration. Electron
Inhibitory effect of 2-deoxy-d-glucose on the formation of the cell wall in yeast protoplasts
Journal of bacteriology, 1969
2-Deoxy-d-glucose (2DG) acted as a competitive inhibitor of the synthesis of cell wall components in Saccharomyces cerevisiae protoplasts. The synthesis of fibrillar glucan cell wall component was inhibited at a glucose to 2DG ratio of 4:1 in the cultivating medium. The completion of the formation of cell wall by the synthesis of the amorphous mannan-protein cell wall component was inhibited at a glucose to 2DG ratio of about 20:1. The inhibition could be reversed by increasing the glucose to 2DG ratio in the nutrient medium. No incorporation of 2DG into fibrillar glucan cell wall component was observed.
Plant Physiology, 1977
The effects of two protein synthesis hinbitors, cydoheximide and chloramphenicol, on the synthesis of nitochondrial proteins in maize (Zea mays) have been studied. The results of these investigations suggest that while most of the mitochondrial proteins are synthesized in the cytoplasm and are subsequently asociated wth the nitochondrion, several proteins of the mitochondrial inner membrane are synthesized within the mitochondrion. These resut are consistent with those observed in several other systems, but not previously reported for higher p-ts. of CH or CAP. The sets were then mixed and homogenized. The 3H incorporation thus served as an internal standard, and the 3H/ 14C ratio served as an indicator of the influence of the protein synthesis inhibitors. SUBCELLULAR FRACTIONS Various subcellular fractions were obtained as described by Longo and Longo (10). Three fractions were studied, namely the soluble fraction (25,000g supernatant), the mitochondrial fraction (which banded at an isopycnic density of 1.22 g/cm3 in a 35-65% sucrose gradient), and the dense particulate fraction which passed through the 65% sucrose in the gradients. This fraction contained mitochondrial inner membranes and glyoxysomes. In higher organisms, protein synthesis occurs on both 80S (cytoplasmic) and 70S (mitochondrial) ribosomes. In yeast, Neurospora, and mammals (2, 13, 14, 16), less than 10% of the
Algological Studies/Archiv für Hydrobiologie, Supplement Volumes, 2000
Ultrastructural examination of three glucosamine-type Chlorella species (C. vulgaris var. vulgaris, C. kessleri, C. sorokiniana), forming a related group in phylogenetic trees inferred from 18S rRNA gene sequences (FRIEDL 1995, Huss et al. 1999), revealed a similar cell ultrastructure but some differences in early and later stages of the cell wall development. All species mentioned above contain the monosaccharide glucosamine as the main constituent of the rigid cell wall (TAKEDA 1991, 1993a, 1993b). A thin electrondense layer is the first visible' structure covering the young daughter protoplasts of C. vulgaris and C. sorokiniana. Layered microfibrils can be observed in cross-sections of adult cell walls. Remnants of the broken maternal cell walls (MCW) persist in a culture medium. In C. kessleri the initial electrondense layer was not found. The cell wall is hardly visible, no rrricrofibrillar structure was detected. No MCW remnants were found in the medium. Negatively stained microfibrils of all the three species obtained by IN NaOH and 2M TFAA treatment are straight or slightly bent. The pyrenoid is transversed by two thylakoids. The rigid cell wall of C. luteoviridis is composed of glucose and mannose (TAKEDA 1991, 1993a, 1993b). However some ultrastructural features of C. luteoviridis resemble that of glucosamine-type cWorellas (the thin electrondense layer covering the young daughter protoplasts, microfibrillar structure of the adult cell wall visible on cross-sections, MCW remnants persisting in a medium). Microfibrils do not form a net, they are kinked and flexuous. C. luteoviridis differs from glucosamine-type species in the pyrenoid structure (the pyrenoid is bisected by four or two thylakoids). Thickness of microfibrils in all studied species is about 5 nm.
Journal of Cell Biology, 1972
Electrophoresis of thylakoid membrane polypeptides from Chlamydomonas reinhardi revealed two major polypeptide fractions . But electrophoresis of the total protein of green cells showed that these membrane polypeptides were not major components of the cell. However, a polypeptide fraction whose characteristics are those of fraction c (a designation used for reference in this paper), one of the two major polypeptides of thylakoid membranes, was resolved in the electrophoretic pattern of total protein of green cells . This polypeptide could not be detected in dark-grown, etiolated cells . Synthesis of the polypeptide occurred during greening of etiolated cells exposed to light . When chloramphenicol (final concentration, 200 )ug/ml) was added to the medium during greening to inhibit chloroplastic protein synthesis, synthesis of chlorophyll and formation of thylakoid membranes were also inhibited to an extent resulting in levels of chlorophyll and membranes 20-25% of those found in control cells . However, synthesis of fraction c was not affected by the drug . This polypeptide appeared in the soluble fraction of the cell under these conditions, indicating that this protein was synthesized in the cytoplasm as a soluble component . When normally greening cells were transferred from light to dark, synthesis of the major membrane polypeptides decreased . Also, it was found that synthesis of both subunits of ribulose 1,5-diphosphate carboxylase was inhibited by chloramphenicol, and that synthesis of this enzyme stopped when cells were transferred from light to dark .
FEMS Microbiology Letters, 1993
Aculeacin A and papulacandin B block cell wall regeneration in Candida albicans protoplasts at an intermediate step in which the protoplasts have not yet synthesized the rigid structure of the cell wall and are therefore still osmotically sensitive. In the presence of the antibiotics, total synthesis of glucan is not significantly lowered with respect to control cells, although most of it appears either in the culture medium or in the regenerating wall as alkali-soluble glucan. Thus, it is proposed that echinocandins (such as aculeacin A) and papulacandins may not inhibit glucan synthesis per se but instead inhibit its incorporation into the supramolecular organization of the cell wall.
Annals of Botany, 2014
† Background and Aims Brown algae are photosynthetic multicellular marine organisms evolutionarily distant from land plants, with a distinctive cell wall. They feature carbohydrates shared with plants (cellulose), animals (fucose-containing sulfated polysaccharides, FCSPs) or bacteria (alginates). How these components are organized into a three-dimensional extracellular matrix (ECM) still remains unclear. Recent molecular analysis of the corresponding biosynthetic routes points toward a complex evolutionary history that shaped the ECM structure in brown algae. † Methods Exhaustive sequential extractions and composition analyses of cell wall material from various brown algae of the order Fucales were performed. Dedicated enzymatic degradations were used to release and identify cell wall partners. This approach was complemented by systematic chromatographic analysis to study polymer interlinks further. An additional structural assessment of the sulfated fucan extracted from Himanthalia elongata was made. † Key Results The data indicate that FCSPs are tightly associated with proteins and cellulose within the walls. Alginates are associated with most phenolic compounds. The sulfated fucans from H. elongata were shown to have a regular a-(1 3) backbone structure, while an alternating a-(1 3), (1 4) structure has been described in some brown algae from the order Fucales. † Conclusions The data provide a global snapshot of the cell wall architecture in brown algae, and contribute to the understanding of the structure-function relationships of the main cell wall components. Enzymatic cross-linking of alginates by phenols may regulate the strengthening of the wall, and sulfated polysaccharides may play a key role in the adaptation to osmotic stress. The emergence and evolution of ECM components is further discussed in relation to the evolution of multicellularity in brown algae.