Compartmentalization and spatiotemporal organization of macromolecules in bacteria

Authors

  • Sutharsan Govindarajan,

    1. Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University – Hadassah Medical School, Jerusalem, Israel
    Search for more papers by this author
  • Keren Nevo-Dinur,

    1. Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University – Hadassah Medical School, Jerusalem, Israel
    Search for more papers by this author
  • Orna Amster-Choder

    Corresponding author
    • Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University – Hadassah Medical School, Jerusalem, Israel
    Search for more papers by this author

Correspondence: Orna Amster-Choder, Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University – Hadassah Medical School, PO Box 12272, Jerusalem 91120, Israel. Tel.: +972 2 675 8460; fax: +972 2 675 7910;

e-mail: amster@cc.huji.ac.il

Abstract

For many years, the bacterial cells were regarded as tiny vessels lacking internal organization. This view, which stemmed from the scarcity of membrane-bounded organelles, has changed considerably in recent years, mainly due to advancements in imaging capabilities. Consequently, despite the rareness of conventional organelles, bacteria are now known to have an intricate internal organization, which is vital for many cellular processes. The list of bacterial macromolecules reported to have distinct localization patterns is rapidly growing. Moreover, time-lapse imaging revealed the spatiotemporal dynamics of various bacterial macromolecules. Although the regulatory mechanisms that underlie macromolecules localization in bacterial cells are largely unknown, certain strategies elucidated thus far include the establishment of cell polarity, the employment of cytoskeletal proteins, and the use of the membrane properties, that is, curvature, electric potential, and composition, as localization signals. The most surprising mechanism discovered thus far is targeting of certain mRNAs to the subcellular domains where their protein products are required. This mechanism relies on localization features in the mRNA itself and does not depend on translation. Localization of other mRNAs near their genetic loci suggests that the bacterial chromosome is involved in organizing gene expression. Taken together, the deep-rooted separation between cells with nucleus and without is currently changing, highlighting bacteria as suitable models for studying universal mechanisms underlying cell architecture.

Ancillary