Speaker
Description
Maintenance of multicellular tissue architecture is conserved process which is regulated by a highly
conserved set of proteins. The interacting partners of these regulators are also conserved across the
animal kingdom. Scribble and Dlg are two such key polarity regulators that involve in the establishment
and maintenance of multicellular apical-basal cell polarity in epithelial cells. These are scaffolding
proteins bearing multiple PDZ domains that mediate most of their interactions. Complex multicellular
organisms evolved from the simple primitive forms; therefore, we examined Scribble and Dlg mediated
cell polarity in the simplest metazoan living on earth, Placazoa, Trichoplax adhaerens. Despite its
extreme simplicity, Trichoplax contains all polarity regulators that are fundamental to instruct the body
plans in higher animals; thus, making it an ideal candidate to use as a polarity studying model. We now
show biochemically that a key interaction for the establishment of cell polarity between Scribble and
Dlg PDZ domains and Vangl in mammals is fully recapitulated in Trichoplax. We found that Scribble
PDZ1, PDZ2 and PDZ3 interact with Vangl with affinities comparable to the human interaction, with
a similar hierarchy in affinities. We also found that all three PDZ domains of Dlg interact with Vangl
with no hierarchy of their affinities. We then show using crystal structures of Scribble PDZ1, PDZ2 and
Dlg PDZ1, PDZ2 bound to the C-terminal PDZ binding motif of Vangl that in addition to the binding
affinities, the detailed interactions between Scribble/Vangl and Dlg/Vangl are also conserved at the
atomic level between Trichoplax and human.
| Level of Expertise | Student |
|---|---|
| Which facility did you use for your research | Australian Synchrotron |
| Do you wish to take part in the Student Poster Slam | Yes |
| Presenter Gender | Woman |
| Students Only - Are you interested in AINSE student funding | Yes |
| Condition of submission | Yes |
