Format

Send to

Choose Destination
Trends Biochem Sci. 2016 Feb;41(2):175-189. doi: 10.1016/j.tibs.2015.09.005. Epub 2015 Oct 28.

Type III Secretion: Building and Operating a Remarkable Nanomachine.

Author information

1
KU Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Laboratory of Molecular Bacteriology, 3000 Leuven, Belgium; Institute of Molecular Biology and Biotechnology, FORTH, University of Crete, PO Box 1385, Iraklio, Crete, GR-711 10 Greece; Department of Biology, University of Crete, PO Box 1385, GR-711 10 Iraklio, Crete, Greece.
2
KU Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Laboratory of Molecular Bacteriology, 3000 Leuven, Belgium; Institute of Molecular Biology and Biotechnology, FORTH, University of Crete, PO Box 1385, Iraklio, Crete, GR-711 10 Greece.
3
KU Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Laboratory of Molecular Bacteriology, 3000 Leuven, Belgium.
4
KU Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Laboratory of Molecular Bacteriology, 3000 Leuven, Belgium; Institute of Molecular Biology and Biotechnology, FORTH, University of Crete, PO Box 1385, Iraklio, Crete, GR-711 10 Greece; Department of Biology, University of Crete, PO Box 1385, GR-711 10 Iraklio, Crete, Greece. Electronic address: tassos.economou@rega.kuleuven.be.

Abstract

The Type III secretion system (T3SS) is a protein export pathway that is widespread in Gram-negative bacteria and delivers effector proteins directly into eukaryotic cells. At its core lie the injectisome (a sophisticated transmembrane secretion apparatus) and a complex network of specialized chaperones that target secretory proteins to the antechamber of the injectisome. The assembly of the system, and the subsequent secretion of proteins through it, undergo fine-tuned, hierarchical regulation. Here, we present the current understanding of the injectisome assembly process, secretion hierarchy, and the role of chaperones. We discuss these events in light of available structural and biochemical dissection and propose future directions essential to revealing mechanistic insight into this fascinating nanomachine.

KEYWORDS:

Type III secretion (T3S); Type III secretion system (T3SS); chaperones; energy requirements; injectisome assembly; secretion regulation

PMID:
26520801
DOI:
10.1016/j.tibs.2015.09.005
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center