Article
- The EMBO Journal (1997) 16, 6394 - 6406
- doi:10.1093/emboj/16.21.6394
The chaperone-assisted membrane release and folding pathway is sensed by two signal transduction systems
C. Hal Jones1, Paul N. Danese2, Jerome S. Pinkner1, Thomas J. Silhavy2 and Scott J. Hultgren1
- Department of Molecular Microbiology, Washington University Medical School, Box 8230, 660 South Euclid Avenue, St Louis, MO 63110, USA
- Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA
Correspondence to:
Scott J. Hultgren,
Received 2 June 1997; Revised 28 July 1997
Abstract
The assembly of interactive protein subunits into extracellular structures, such as pilus fibers in the Enterobacteriaceae, is dependent on the activity of PapD-like periplasmic chaperones. The ability of PapD to undergo a 
zippering interaction with the hydrophobic C-terminus of pilus subunits facilitates their folding and release from the cytoplasmic membrane into the periplasm. In the absence of the chaperone, subunits remained tethered to the membrane and were driven off-pathway via non-productive interactions. These off-pathway reactions were detrimental to cell growth; wild-type growth was restored by co-expression of PapD. Subunit misfolding in the absence of PapD was sensed by two parallel pathways: the Cpx two-component signaling system and the 
E modulatory pathway.
Keywords:
- chaperone,
- periplasmic stress,
- periplasmic targeting,
- protein folding,
- signal transduction
