TY - JOUR
T1 - Protein localization and dynamics within a bacterial organelle
AU - Hughes, H. Velocity
AU - Huitema, Edgar
AU - Pritchard, Sean
AU - Keiler, Kenneth C.
AU - Brun, Yves V.
AU - Viollier, Patrick H.
PY - 2010/3/23
Y1 - 2010/3/23
N2 - Protein localization mechanisms dictate the functional and structural specialization of cells. Of the four polar surface organelles featured by the dimorphic bacterium Caulobacter crescentus, the stalk, a cylindrical extension of all cell envelope layers, is the least well characterized at the molecular level. Here we apply a powerful experimental scheme that integrates genetics with high-throughput localization to discover StpX, an uncharacterized bitopic membrane protein that modulates stalk elongation and is sequestered to the stalk. In stalkless mutants StpX is dispersed. Two populations of StpX were discernible within the stalk with different mobilities: an immobile one near the stalk base and a mobile one near the stalk tip. Molecular anatomy provides evidence that (i) the StpX transmembrane domain enables access to the stalk organelle, (ii) the N-terminal periplasmic domain mediates retention in the stalk, and (iii) the C-terminal cytoplasmic domain enhances diffusion within the stalk. Moreover, the accumulation of StpX and an N-terminally truncated isoformis differentially coordinated with the cell cycle. Thus, at the submicron scale the localization and the mobility of a protein are precisely regulated in space and time and are important for the correct organization of a subcellular compartment or organelle such as the stalk.
AB - Protein localization mechanisms dictate the functional and structural specialization of cells. Of the four polar surface organelles featured by the dimorphic bacterium Caulobacter crescentus, the stalk, a cylindrical extension of all cell envelope layers, is the least well characterized at the molecular level. Here we apply a powerful experimental scheme that integrates genetics with high-throughput localization to discover StpX, an uncharacterized bitopic membrane protein that modulates stalk elongation and is sequestered to the stalk. In stalkless mutants StpX is dispersed. Two populations of StpX were discernible within the stalk with different mobilities: an immobile one near the stalk base and a mobile one near the stalk tip. Molecular anatomy provides evidence that (i) the StpX transmembrane domain enables access to the stalk organelle, (ii) the N-terminal periplasmic domain mediates retention in the stalk, and (iii) the C-terminal cytoplasmic domain enhances diffusion within the stalk. Moreover, the accumulation of StpX and an N-terminally truncated isoformis differentially coordinated with the cell cycle. Thus, at the submicron scale the localization and the mobility of a protein are precisely regulated in space and time and are important for the correct organization of a subcellular compartment or organelle such as the stalk.
UR - http://www.scopus.com/inward/record.url?scp=77950378099&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77950378099&partnerID=8YFLogxK
U2 - 10.1073/pnas.0909119107
DO - 10.1073/pnas.0909119107
M3 - Article
C2 - 20212131
AN - SCOPUS:77950378099
SN - 0027-8424
VL - 107
SP - 5599
EP - 5604
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 12
ER -