Microtubule-like properties of the bacterial actin homolog ParM-R1.
In preparation for mammalian cell division, microtubules repeatedly probe the cytoplasm to capture chromosomes and assemble the mitotic spindle. Critical features of this microtubule system are the formation of radial arrays centered at the centrosomes and dynamic instability, leading to persistent cycles of polymerization and depolymerization. Here, we show that actin homolog, ParM-R1 that drives segregation of the R1 multidrug resistance plasmid from Escherichia coli, can also self-organize in vitro into asters, which resemble astral microtubules. ParM-R1 asters grow from centrosome-like structures consisting of interconnected nodes related by a pseudo 8-fold symmetry. In addition, we show that ParM-R1 is able to perform persistent microtubule-like oscillations of assembly and disassembly. In vitro, a whole population of ParM-R1 filaments is synchronized between phases of growth and shrinkage, leading to prolonged synchronous oscillations even at physiological ParM-R1 concentrations. These results imply that the selection pressure to reliably segregate DNA during cell division has led to common mechanisms within diverse segregation machineries.
Institute of Molecular and Cell Biology, Proteos, 61 Biopolis Drive, 138673, Singapore. dpopp@imcb.a-star.edu.sg
David
D
Popp
Akihiro
A
Narita
Lin Jie
LJ
Lee
Mårten
M
Larsson
Robert C
RC
Robinson
D000199:Actins / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D000255:Adenosine Triphosphate / Q000737:chemistry; D019943:Amino Acid Substitution; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D005583:Fourier Analysis; D006160:Guanosine Triphosphate / Q000737:chemistry; D006868:Hydrolysis; D008027:Light; D008870:Microtubules / Q000737:chemistry*; D016297:Mutagenesis, Site-Directed; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D012542:Scattering, Radiation
D000199:Actins; D029968:Escherichia coli Proteins; C471255:ParM protein, E coli; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate