Caulobacter PopZ forms a polar subdomain dictating sequential changes in pole composition and function.
The bacterium Caulobacter crescentus has morphologically and functionally distinct cell poles that undergo sequential changes during the cell cycle. We show that the PopZ oligomeric network forms polar ribosome exclusion zones that change function during cell cycle progression. The parS/ParB chromosomal centromere is tethered to PopZ at one pole prior to the initiation of DNA replication. During polar maturation, the PopZ-centromere tether is broken, and the PopZ zone at that pole then switches function to act as a recruitment factor for the ordered addition of multiple proteins that promote the transformation of the flagellated pole into a stalked pole. Stalked pole assembly, in turn, triggers the initiation of chromosome replication, which signals the formation of a new PopZ zone at the opposite cell pole, where it functions to anchor the newly duplicated centromere that has traversed the long axis of the cell. We propose that pole-specific control of PopZ function co-ordinates polar development and cell cycle progression by enabling independent assembly and tethering activities at the two cell poles.
Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Grant R
GR
Bowman
Luis R
LR
Comolli
Guido M
GM
Gaietta
Michael
M
Fero
Sun-Hae
SH
Hong
Ying
Y
Jones
Julie H
JH
Lee
Kenneth H
KH
Downing
Mark H
MH
Ellisman
Harley H
HH
McAdams
Lucy
L
Shapiro
D001426:Bacterial Proteins / Q000378:metabolism*; D016935:Caulobacter crescentus / Q000378:metabolism / Q000502:physiology*; D002453:Cell Cycle; D016764:Cell Polarity; D002503:Centromere / Q000378:metabolism; D002876:Chromosomes, Bacterial / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008954:Models, Biological; D008958:Models, Molecular; D055503:Protein Multimerization
D001426:Bacterial Proteins; D004269:DNA, Bacterial