One of the universal traits of microorganisms is their ability to form multicellular structures, the cells of which differentiate and communicate via various signaling molecules. Reactive oxygen species (ROS), and hydrogen peroxide in particular, have recently become well-established signaling molecules in higher eukaryotes, but still little is known about the regulatory functions of ROS in microbial structures. Here we summarize current knowledge on the possible roles of ROS during the development of colonies and biofilms, representatives of microbial multicellularity. In Saccharomyces cerevisiae colonies, ROS are predicted to participate in regulatory events involved in the induction of ammonia signaling and later on in programmed cell death in the colony center. While the latter process seems to be induced by the total ROS, the former event is likely to be regulated by ROS-homeostasis, possibly H(2)O(2)-homeostasis between the cytosol and mitochondria. In Candida albicans biofilms, the predicted signaling role of ROS is linked with quorum sensing molecule farnesol that significantly affects biofilm formation. In bacterial biofilms, ROS induce genetic variability, promote cell death in specific biofilm regions, and possibly regulate biofilm development. Thus, the number of examples suggesting ROS as signaling molecules and effectors in the development of microbial multicellularity is rapidly increasing.

• MeSH
• Bacteria cytologie   metabolismus   MeSH
• fyziologická adaptace * MeSH
• houby cytologie   metabolismus   MeSH
• mikrobiální společenstva fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• reaktivní formy kyslíku MeSH

We have shown previously that iron deprivation significantly stimulates the uptake of non-transferrin ferric iron from ferric citrate by erythroleukemia K562 cells and that this stimulation depends on protein synthesis. However, we have not detected increased expression of any known iron transport protein (Kovar J. et al. (2006) Blood Cells Mol Dis 37:95-99). Therefore, in order to identify membrane proteins of K562 cells with increased expression under iron deprivation, we employed the isolation of membrane proteins by two-phase partitioning system, protein separation by high-resolution 2D electrophoresis, computer differential analysis, and tandem mass spectrometry. Employing these techniques we identified two proteins with statistically significant upregulation, i.e., aldolase A (ALDA) and voltage-dependent anion channel 2 (VDAC2). The upregulation of aldolase A and VDAC2 in K562 cells under iron deprivation was also confirmed by western blot analysis. This is the first time when the control of aldolase A and VDAC2 levels by iron status of the cell is demonstrated.

• MeSH
• aldolasa genetika   metabolismus   MeSH
• buňky K562 * MeSH
• deficit železa * MeSH
• lidé MeSH
• napětím ovládaný aniontový kanál 2 genetika   metabolismus   MeSH
• regulace genové exprese * MeSH
• upregulace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aldolasa MeSH
• napětím ovládaný aniontový kanál 2 MeSH
• VDAC2 protein, human MeSH Prohlížeč