title: Getting across the cell envelope: mycobacterial protein secretion.
abstract: Protein secretion is an essential determinant of mycobacterial virulence. Mycobacterium tuberculosis has a unique cell envelope consisting of two lipid bilayers, which requires dedicated protein secretion pathways. The conserved general Sec and Tat translocation systems are responsible for protein transport across the inner membrane and are both essential. Additionally, the accessory Sec pathway specifically contributes to virulence. How transport of Sec/Tat substrates across the outer membrane is accomplished is currently an enigma. In addition to these pathways, M. tuberculosis also developed specialized secretion systems for protein transport across both membranes, the type VII or ESX secretion systems. Here, we discuss our current knowledge about the mechanisms and substrates of these different protein translocation systems and their role in mycobacterial physiology and virulence.
authors.affiliation: Department of Molecular Microbiology, Institute of Molecular Cell Biology, VU University, Amsterdam, The Netherlands.
authors.forename: Aniek D
authors.initials: AD
authors.lastname: van der Woude
authors.forename: Joen
authors.initials: J
authors.lastname: Luirink
authors.forename: Wilbert
authors.initials: W
authors.lastname: Bitter
mesh_terms: D016667:Bacterial Capsules / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism; D008264:Macrophages / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000378:metabolism* / Q000472:pathogenicity; D021381:Protein Transport; D014397:Tuberculosis, Pulmonary / Q000382:microbiology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D007501:Iron