Dr ali shakeri
In eukaryotic cells, the actin cytoskeleton regulates a variety of functions. Due to its importance in these diverse cellular processes, the actin cytoskeleton is also a critical target of intracellular bacterial pathogens. Many pathogens hijack actin at different steps of their life cycle. Understanding the mechanism of movement helps the prevention of bacterial infections. The aim of this study was to investigate the mechanisms of actin base motility of bacterial pathogens. The study focused on four microbial pathogens genera; including Listeria monocytogenes, Shigella flexneri Burkholderia spp. in the Pseudomallei group, and spotted fever group (SFG) Rickettsia spp. These pathogens share common mechanisms of infection. To compare this phenomenon, the searching process was performed through PubMed and Google Scholar databases. Accordingly, our review showed a critical role for the host Arp2/3 complex and its nucleation promoting factors (NPFs) in actin assembly. As we know the diverse biochemical mechanisms of actin polymerization are used by pathogens, resulting in divergent actin filament organization and consequently motility. These are dynamic and complicated processes coordinated by a network of host and bacterial factors. New studies provide new information on an intracellular movement; for example, in addition to RickA, SFG Rickettsiae also express Sca2, a mimic of host formin proteins, which directly nucleates actin and promotes filament elongation by progressively relatedness to the barbed end of an actin filament and preventing the host capping protein activity. Our results showed that the bacteria capable of actin-based motility subvert a variety of host factors to promote movement. However, we still do not know how all of these factors are recruited or their precise mechanism of action. Moreover, we do not know whether each pathogen hijacks a unique profile of cytoskeletal and regulatory proteins that may reflect distinct modes of actin-based movement. For understand this subject more research is needed.