The Molecular Structures and Function of the Yeast Saccharomyces cerevisiae Cell Wall / 대한의진균학회지

The main characteristics of molecular structures of the yeast Saccharomyces cerevisiae cell wall are now elucidated. The cell wall of Saccharomyces cerevisiae is composed of inner layer and outer layer and is the structure that plays an important role of providing physical and chemical protection and deciding the morphology of the cell. The inner layer of the cell wall is responsible for the mechanical strength of the wall and also providing the attachment sites for the proteins that form the outer layer of the cell wall. The outer protein layer limits the permeability of the cell wall, therefore, shields the plasma membrane from perturbation stimuli by foreign material such as enzymes and other chemicals. The molecular composition and organization of the cell wall may vary according to the environmental circumstances. The formation and genetic control of the specific cell wall protein-polysaccharide complexes is influenced by external conditions and stimuli. Cell wall construction is tightly controlled and strictly coordinated with progression of the cell cycle. This is reflected in the usage of specific cell wall proteins during consecutive phases of the cell cycle and in the recent discovery of a cell wall integrity checkpoint.

Study on apoptosis of K562 cells induced by tumor-bearing herb serum of selenium-protein polysaccharide extracted from Qinba selenium-mushroom(秦巴硒菇) / 中国中西医结合急救杂志

Objective: To explore the effect of selenium-protein polysaccharide extracted from Qinba (selenium-mushroom)(秦巴硒菇) on apoptosis of K562 cells.Methods: Tumor-bearing mice model was established,and selenium-protein polysaccharide extracted from Qinba selenium-mushroom contained-herb serum was prepared by the method of serum pharmacology.K562 cells were conventionally cultured.Growth inhibition rate of tumor cells was detected by methyl thiazolyl tetrazolium(MTT) method.Morphological changes of apoptotic cell were observed under a fluorescent microscope.Cell apoptosis was observed by DNA electrophoresis.Caspase3 relative gene was measured by colorimetry.Results: Selenium-protein(polysaccharide) extracted from Qinba selenium-mushroom could significantly inhibit the growth of K562 cells,there was a remarkably positive correlation between drug concentration,time and inhibitory rate.Apoptotic phenomenon was certained via morphological examination and DNA electrophoresis.Compared with control group,caspase3 gene was markedly upregulated.Conclusion: Selenium-protein(polysaccharide) extracted from Qinba selenium-mushroom could induce apoptosis of K562 cells.The mechanism may be related to upregulation of caspase3.