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Reference.org
Type II secretion system
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<p>The type 2 secretion system (often referred to as the type II secretion system or by the initials T2SS) is a type of protein <a href="/facts/Secretion/VHk9eLAV">secretion</a> machinery found in various species of <a href="/facts/Gram-negative_bacteria/S1PbVtp4">Gram-negative bacteria</a>, including many human <a href="/facts/Pathogens/axMXtV1M">pathogens</a> such as <i><a href="/facts/Pseudomonas_aeruginosa/HBhyIxAn">Pseudomonas aeruginosa</a></i> and <i><a href="/facts/Vibrio_cholerae/DbjgMz9Y">Vibrio cholerae</a></i>. The type II secretion system is one of six protein secretory systems commonly found in Gram-negative bacteria, along with the <a href="/facts/Secretion/VHk9eLAV">type I</a>, <a href="/facts/Type_III_secretion_system/WL4VW48e">type III</a>, and <a href="/facts/Secretion/VHk9eLAV">type IV</a> secretion systems, as well as the <a href="/facts/Chaperone-Usher_fimbriae/30SgxJPm">chaperone/usher pathway</a>, the <a href="/facts/Secretion/VHk9eLAV">autotransporter pathway/type V secretion system</a>, and the <a href="/facts/Secretion/VHk9eLAV">type VI secretion system</a> (some bacteria also utilize the <a href="/facts/Type_VII_secretion_system/c7K5GeJr">type VII secretion system</a>). Like these other systems, the type II secretion system enables the transport of cytoplasmic proteins across the <a href="/facts/Lipid_bilayers/CQKQ9l3g">lipid bilayers</a> that make up the cell membranes of Gram-negative bacteria. Secretion of proteins and <a href="/facts/Effector_(biology)/hGT8owD9">effector</a> molecules out of the cell plays a critical role in signaling other cells and in the invasion and parasitism of host cells. </p>