title: Coiled-coil protein Scy is a key component of a multiprotein assembly controlling polarized growth in Streptomyces.
abstract: Polarized growth in eukaryotes requires polar multiprotein complexes. Here, we establish that selection and maintenance of cell polarity for growth also requires a dedicated multiprotein assembly in the filamentous bacterium, Streptomyces coelicolor. We present evidence for a tip organizing center and confirm two of its main components: Scy (Streptomyces cytoskeletal element), a unique bacterial coiled-coil protein with an unusual repeat periodicity, and the known polarity determinant DivIVA. We also establish a link between the tip organizing center and the filament-forming protein FilP. Interestingly, both deletion and overproduction of Scy generated multiple polarity centers, suggesting a mechanism wherein Scy can both promote and limit the number of emerging polarity centers via the organization of the Scy-DivIVA assemblies. We propose that Scy is a molecular "assembler," which, by sequestering DivIVA, promotes the establishment of new polarity centers for de novo tip formation during branching, as well as supporting polarized growth at existing hyphal tips.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Holmes
authors.forename: John
authors.initials: J
authors.lastname: Walshaw
authors.forename: Richard M
authors.initials: RM
authors.lastname: Leggett
authors.forename: Annabelle
authors.initials: A
authors.lastname: Thibessard
authors.forename: Kate A
authors.initials: KA
authors.lastname: Dalton
authors.forename: Michael D
authors.initials: MD
authors.lastname: Gillespie
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Hemmings
authors.forename: Bertolt
authors.initials: B
authors.lastname: Gust
authors.forename: Gabriella H
authors.initials: GH
authors.lastname: Kelemen
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division; D016764:Cell Polarity; D002473:Cell Wall / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation; D011485:Protein Binding; D048372:Streptomyces coelicolor / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C104636:DivIVA protein, bacteria; D046912:Multiprotein Complexes