Mitochondrial Calcium: Effects of Its Imbalance in Disease.

Calcium is used in many cellular processes and is maintained within the cell as free calcium at low concentrations (approximately 100 nM), compared with extracellular (millimolar) concentrations, to avoid adverse effects such as phosphate precipitation. For this reason, cells have adapted buffering strategies by compartmentalizing calcium into mitochondria and the endoplasmic reticulum (ER). In mitochondria, the calcium concentration is in the millimolar range, as it is in the ER.

Chitosan resistance by the deletion of the putative high affinity glucose transporter in the yeast Ustilago maydis.

Chitosan is a polycationic amino-sugar polymer soluble in acidic pH. As a potential antifungal, it has been tested against several fungi. Its main mode of action is the permeabilization of cell membrane by the interaction with specific membrane sites.

Roles of bacterial membrane vesicles.

Outer membrane vesicles (OMVs) are released from the outer membrane of Gram-negative bacteria. Moreover, Gram-positive bacteria also produce membrane-derived vesicles. As OMVs transport several bacterial components, especially from the cell envelope, their interaction with the host cell, with other bacteria or as immunogens, have been studied intensely.