Subcellular protoplasts

Hrazdina G, Wagner GJ, Siegelman HW. 1978. Subcellular localization of enzymes of anthocyanin biosynthesis in protoplasts. Phytochem 17 53-56. 

I. S. Kulaev (1973). The enzymes of polyphosphate metabolism in protoplasts and some subcellular structures of Neurospora crassa. In J. Villanueva (Ed.), Yeast Mould and Plant Protoplasts, Academic Press, London, p. 259. 

I. S. Kulaev, T. P. Afanas eva, I. A. Krasheninnikov and S. E. Mansurova (1970a). Phosphorus compounds in protoplasts of Endomyces magnusii and Neurospora crassa and their subcellular structures. Acta. Fac. Med. Univ. Brun., 37, 81-90. 

Figure 1-1 depicts a representative leaf cell from a higher plant and illustrates the larger subcellular structures. The living material of a cell, known as the protoplast, is surrounded by the cell wall. The cell wall is composed of cellulose and other polysaccharides, which helps provide rigidity to... 

Fairbaim and Williamson studied P. bracteatum anatomically and compared it to P. somniferum (18). They found the two plants to be very similar in stmcture. The laticifers of P. bracteatum were usually more closely packed and anastomose more frequently. The subcellular fraction of protoplasts from cultured P. bracteatum cells (organelles sedimenting at 1000 g) was the major site where thebaine and sanguinarine accumulated (19). It also contained dopamine as a precursor and the vacuolar enzyme a-mannosidase. Dopamine also appeared in the supernatant. Dopamine compartmentalization in vacuoles of cultured cells was observed by histofluorescence microscopy. Dopamine, sanguinarine, and thebaine occurred in vacuoles of different densities. This result is consistent with... 

From the perspective of cell lysis, this mannoprotein layer serves to protect the glucans from hydrolytic enzymes (18,19,20). Within the two wall layers is the protoplast, comprised of a plasma membrane enclosing the cytosol and the subcellular structures. 

Structured model. This model considers lysis of the cell from the viewpoint of progressive breakdown of the cell structures, starting from the outer wall layer and progressing to the subcellular structures inside the protoplast (35). Here the cell is divided into... 

The subcellular localization of the starch biosynthetic and degradative enzymes of spinach leaves was carried out by measuring the distribution of the enzymes in a crude chloroplast pellet and in separated components of a protoplast lysate. The enzymes which were involved in the syntheses of starch were detected in the chloroplasts, whereas some of the enzymes involved in the degradation of starch were mainly in the soluble protein fraction but were also found in the chloroplast. The digestion pattern of the amylase on amylopectin as substrate indicated that the enzyme was an a-amylase from its endo-lytic activity, but displayed properties unlike the typical a-amylase isolated from endosperm tissue. A time-sequence analysis of the starch digestion pattern in germinating... 

TABLE 3. Effect of oligomycin on subcellular levels of metabolites in barley leaf protoplasts. 

TABLE 1. The subcellular content of TP and PGA in protoplasts incubated in saturating light for 5-7 min under different conditions with respect to photorespiration. In "limiting CO" the rate of photosynthetic 0 production was 15-25% of the rate in saturating CO (10 mM NaHCO ). The results are the mean + SD from 3 to 4 experiments. 

Subcellular localization of chorismate-mutase isoenz3nnes in protoplasts from mesophyll and suspension-cultured cells of Nicotiana silvestris. Planta 162 104-108. 

A modified procedure for studying the secretion of /S-o-fructofuranosidase in yeast sphaeroplasts, and the subcellular distribution of the enzyme have been reported. The levels of /S-o-fructofuranosidase in yeasts are regulated by binding the secreted enzyme to the cell surface. The synthesis of jS-o-fructo-furanosidase by the cells and the protoplasts of the yeast Pichia polymorpha was affected by the presence of 2-deoxy-D-flra6mo-hexose in the culture medium. ... 

B. Ohlrogge, D. N. Kuhn and P. K. Stumpf, Subcellular localisation of acyi carrier protein in leaf protoplasts of Spinacia oleracea, Proc. Natl. Acad. Sci. USA 76 1194 (1979). 

One of our first observations was on the subcellular distribution of ACP In spinach mesophyll cells. In 1979 we found that when protoplasts were gently lysed and their organelles seperated on sucrose gradients, essentially all of the ACP present could be attributed to the chloroplast fraction (2). This result revealed that plant mesophyll cells differ from animal and fungal cells by the absence of fatty acid synthesis In the cytoplasm. It Is now known that plastlds are also a major site of fatty acid synthesis In many non-green plant tissues although It has not been established whether other subcellular sites In these tissues also contribute to FAS. 

Kuhn N, Knauf MJ, Stumpf PK. Subcellular localization of acetyl-CoA synthetase in leaf protoplasts of Spinacia oleracea. Arch Biochem Biophys 1981 209 441-450. Liedvogel B, Stumpf PK. Origin of acetate in spinach leaf cells. Plant Physiol 1982 69 897-903... 

Inhibitors of protein synthesis as chloramphenicol (Bernlohr and Novelli, 1963 Cornell and Snoke, 1964), puromycin, and tetracycline (Cornell and Snore, 1964) do not suppress the formation of bacitracin by either whole cells or protoplasts that had been cultured in or derived from Mn+ -sufficient environments. The quantity of antibiotic produced by subcellular extracts is reduced by the presence of ribonuclease (RNase) but not as profoundly as can be generally observed in a system of protein biosynthesis deoxyribonuclease (DNase) has no effect on bacitracin yield (Shimura et al., 1964). In contrast, the ability of cell free extracts to produce the antibiotic is completely destroyed by detergents as, for example, sodium deoxycholate and sodium la urylsulf ate apparently, intact lipoprotein membranes are essential for the biosynthetic process (Shimura etaL, 1964). 

Yeast cells were treated with snail gut enzymes to form protoplasts and were disrupted by passage through a French pressure cell. Subcellular fractions were prepared and incubated with 2[ H]glycerol-3-phosphate for 30 min, as described by Cobon et al. The results are expressed as molar % phospholipid phosphorus. 

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