Coiled-coil protein Scy is a key component of a multiprotein assembly controlling polarized growth in Streptomyces

Proc Natl Acad Sci U S A. 2013 Jan 29;110(5):E397-406. doi: 10.1073/pnas.1210657110. Epub 2013 Jan 7.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Division
  • Cell Polarity
  • Cell Wall / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Microscopy, Confocal
  • Microscopy, Electron, Transmission
  • Multiprotein Complexes / metabolism*
  • Mutation
  • Protein Binding
  • Streptomyces coelicolor / growth & development*
  • Streptomyces coelicolor / metabolism*
  • Streptomyces coelicolor / ultrastructure

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Cell Cycle Proteins
  • DivIVA protein, bacteria
  • Multiprotein Complexes