TY - JOUR
T1 - Bacterial intermediate filaments
T2 - in vivo assembly, organization, and dynamics of crescentin
AU - Charbon, Godefroid
AU - Cabeen, Matthew T
AU - Jacobs-Wagner, Christine
PY - 2009/5/1
Y1 - 2009/5/1
N2 - Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin also shares in vivo properties of assembly and dynamics with IF proteins by forming stable filamentous structures that continuously incorporate subunits along their length and that grow in a nonpolar fashion. De novo assembly of crescentin is biphasic and involves a cell size-dependent mechanism that controls the length of the structure by favoring lateral insertion of crescentin subunits over bipolar longitudinal extension when the structure ends reach the cell poles. The crescentin structure is stably anchored to the cell envelope, and this cellular organization requires MreB function, identifying a new function for MreB and providing a parallel to the role of actin in IF assembly and organization in metazoan cells. Additionally, analysis of an MreB localization mutant suggests that cell wall insertion during cell elongation normally occurs along two helices of opposite handedness, each counterbalancing the other's torque.
AB - Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin also shares in vivo properties of assembly and dynamics with IF proteins by forming stable filamentous structures that continuously incorporate subunits along their length and that grow in a nonpolar fashion. De novo assembly of crescentin is biphasic and involves a cell size-dependent mechanism that controls the length of the structure by favoring lateral insertion of crescentin subunits over bipolar longitudinal extension when the structure ends reach the cell poles. The crescentin structure is stably anchored to the cell envelope, and this cellular organization requires MreB function, identifying a new function for MreB and providing a parallel to the role of actin in IF assembly and organization in metazoan cells. Additionally, analysis of an MreB localization mutant suggests that cell wall insertion during cell elongation normally occurs along two helices of opposite handedness, each counterbalancing the other's torque.
KW - Bacterial Proteins/chemistry
KW - Caulobacter crescentus/cytology
KW - Cell Cycle/physiology
KW - Chloramphenicol/pharmacology
KW - Cytoskeletal Proteins/chemistry
KW - Escherichia coli/genetics
KW - Escherichia coli Proteins/genetics
KW - Gene Expression Regulation, Bacterial/drug effects
KW - Intermediate Filaments/metabolism
KW - Mutation
KW - Protein Multimerization/drug effects
KW - Protein Synthesis Inhibitors/pharmacology
U2 - 10.1101/gad.1795509
DO - 10.1101/gad.1795509
M3 - Journal article
C2 - 19417107
SN - 0890-9369
VL - 23
SP - 1131
EP - 1144
JO - Genes & Development
JF - Genes & Development
IS - 9
ER -