Essential role of DivIVA in polar growth and morphogenesis in Streptomyces coelicolor A3(2).
Streptomycetes grow by cell wall extension at hyphal tips. The molecular basis for such polar growth in prokaryotes is largely unknown. It is reported here that DivIVASC, the Streptomyces coelicolor homologue of the Bacillus subtilis protein DivIVA, is essential and directly involved in hyphal tip growth and morphogenesis. A DivIVASC-EGFP hybrid was distinctively localized to hyphal tips and lateral branches. Reduction of divIVASC expression to about 10% of the normal level produced a phenotype strikingly similar to that of many tip growth mutants in fungi, including irregular curly hyphae and apical branching. Overexpression of the gene dramatically perturbed determination of cell shape at the growing tips. Furthermore, staining of nascent peptidoglycan with a fluorescent vancomycin conjugate revealed that induction of overexpression in normal hyphae disturbed tip growth, and gave rise to several new sites of cell wall assembly, effectively causing hyperbranching. The results show that DivIVASC is a novel bacterial morphogene, and it is localized at or very close to the apical sites of peptidoglycan assembly in Streptomyces hyphae.
Flärdh
Klas
K
Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, 751 24 Uppsala, Sweden. klas.flardh@icm.uu.se
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D002462:Cell Membrane / Q000648:ultrastructure; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005456:Fluorescent Dyes / Q000378:metabolism; D015870:Gene Expression; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009024:Morphogenesis; D016254:Mutagenesis, Insertional; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000166:cytology* / Q000235:genetics / Q000254:growth & development*
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D004269:DNA, Bacterial; C104636:DivIVA protein, bacteria; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins