Control of cell polarity in C. elegans larval epithelia


Supervising PI

Mike Boxem (website)

Project Description

Background

Epithelial cells are the most common polarized cell type in multicellular organisms. Studies in the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster have identified a series of cortically localized proteins that can drive the establishment of polarity. The PAR3/PAR6/aPKC and Crumbs/SDT/PATJ complexes together promote apical domain identity, while the LGL/SCRIB/DLG proteins promote basolateral identity. Although it is clear that mutual exclusion is a key mechanism by which cortical polarity regulators establish polarity, we still lack a detailed mechanistic understanding of how the cortical polarity regulators are segregated into distinct domains. Moreover, we know little of the mechanisms through which cortical polarity is integrated with cellular events such as cytoskeletal rearrangement, organization of a polarized trafficking machinery, and functional specialization of membrane domains.

Objectives

  • Identification of regulatory interactions between the apical PAR and Crumbs complexes and the basolateral Scribble group of polarity regulators, which have not been studied in detail in elegans larval epithelia.
  • Identification of novel factors important for epithelial polarity through genetic screens and through follow-up of candidates identified in previous high-throughput interaction screens.

Methodology

  • CRISPR/Cas9-mediated genome engineering to generate deletion alleles, specific point mutants, and endogenously tagged fluorescent proteins.
  • Genetic screens.
  • RNAi
  • Tissue-specific protein inactivation using Cre-lox recombination (with the Van den Heuvel group) or ZIF-1 mediated degradation.

Collaborators

Key publications

  1. Waaijers S, Ramalho JJ, Koorman T, Kruse E, Boxem M. The elegans Crumbs family contains a CRB3 homolog and is not essential for viability. Biol Open. 2015;4(3):276–84.
  2. Waaijers S, Boxem M. Engineering the Caenorhabditis elegans genome with CRISPR/Cas9. 2014 Mar 28;68(3):381–8.
  3. Waaijers S, Koorman T, Kerver J, Boxem M. Identification of human protein interaction domains using an ORFeome-based yeast two-hybrid fragment library. J Proteome Res. 2013 Jul 5;12(7):3181–92.
  4. Boxem M, Maliga Z, Klitgord N, Li N, Lemmens I, Mana M, et al. A protein domain-based interactome network for elegans early embryogenesis. Cell. 2008 Aug 8;134(3):534–45.