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Serine protease autotransporters of Enterobacteriaceae (SPATE) constitute a superfamily of virulence factors, resembling the trypsin‐like superfamily of serine proteases. SPATEs accomplish multiple functions associated to disease development of their hosts, which could be the consequence of SPATE cleavage of host cell components. SPATEs have been divided into class‐1 and class‐2 based on structural differences and biological effects, including similar substrate specificity, cytotoxic effects on cultured cells, and enterotoxin activity on intestinal tissues for class‐1 SPATEs, whereas most class‐2 SPATEs exhibit a lectin‐like activity with a predilection to degrade a variety of mucins, including leukocyte surface O‐glycoproteins and soluble host proteins, resulting in mucosal colonization and immune modulation. In this review, the structure of class‐1 and class‐2 are analyzed, making emphasis on their putative functional subdomains as well as a description of their function is provided, including prototypical mechanism of action. [ABSTRACT FROM AUTHOR]

The actin cytoskeleton is a dynamic structure necessary for cell and tissue organization, including the maintenance of epithelial barriers. Disruption of the epithelial barrier coincides with alterations of the actin cytoskeleton in several disease states. These disruptions primarily affect the paracellular space, which is normally regulated by tight junctions. Thereby, the actin cytoskeleton is a common and recurring target of bacterial virulence factors. In order to manipulate the actin cytoskeleton, bacteria secrete and inject toxins and effectors to hijack the host cell machinery, which interferes with host-cell pathways and with a number of actin binding proteins. An interesting model to study actin manipulation by bacterial effectors is Escherichia coli since due to its genome plasticity it has acquired diverse genetic mobile elements, which allow having different E. coli varieties in one bacterial species. These E. coli pathotypes, including intracellular and extracellular bacteria, interact with epithelial cells, and their interactions depend on a specific combination of virulence factors. In this paper we focus on E. coli effectors that mimic host cell proteins to manipulate the actin cytoskeleton. The study of bacterial effector-cytoskeleton interaction will contribute not only to the comprehension of the molecular causes of infectious diseases but also to increase our knowledge of cell biology. [ABSTRACT FROM AUTHOR]