The Rho guanine nucleotide exchange factor Trio is required for neural crest cell migration and interacts with Dishevelled

Abstract

Directional migration during embryogenesis and tumor progression faces the challenge that numerous external signals need to converge to precisely control cell movement. The Rho guanine exchange factor (GEF) Trio is especially well suited to relay signals, as it features distinct catalytic domains to activate Rho GTPases. Here, we show that Trio is required for Xenopus cranial neural crest (NC) cell migration and cartilage formation. Trio cell-autonomously controls protrusion formation of NC cells and Trio morphant NC cells show a blebbing phenotype. Interestingly, the Trio GEF2 domain is sufficient to rescue protrusion formation and migration of Trio morphant NC cells. We show that this domain interacts with the DEP/C-terminus of Dishevelled (DVL). DVLbut not a deletion construct lacking the DEP domainis able to rescue protrusion formation and migration of Trio morphant NC cells. This is likely mediated by activation of Rac1, as we find that DVL rescues Rac1 activity in Trio morphant embryos. Thus, our data provide evidence for a novel signaling pathway, whereby Trio controls protrusion formation of cranial NC cells by interacting with DVL to activate Rac1.

Ptk7 Is Dynamically Localized at Neural Crest Cell–Cell Contact Sites and Functions in Contact Inhibition of Locomotion

“…Thus, the extracellular domain may also be required for Wnt/receptor complex formation and possibly Dvl recruitment, which leads to local activation of RhoGTPases and is involved in CIL downstream signaling. In this context, Ptk7-mediated Dvl recruitment may also support Cadherin-11/Trio signaling, as we have recently shown that the GEF2 domain of Trio interacts with the DEP domain of Dvl [37]. Like Ptk7, Cadherin-11 is required for CIL in NC cells [30].…”

“…Like Ptk7, Cadherin-11 is required for CIL in NC cells [30]. Cadherin-11 interacts with the RhoGEF Trio, which can activate RhoGTPases [37,38]. As Trio was also shown to be important for microtubule catastrophe at the cell-cell contact site [39], this module may provide multiple ways to relay information from the cell-cell contact site to the cytoskeleton.…”

“…Cell lines and culture conditions: H1299 cells (CRL-5803; ATCC, Manassas, VA, USA) were grown in Dulbecco's modified Eagle medium, high glucose (DMEM) supplemented with 10% fetal calf serum (FCS) (Capricorn, Ebsdorfergrund, Germany), 1% GlutaMAX and 1% non-essential amino acids (both from Gibco-Thermo Fisher, Freiburg, Germany) at 37 • C in a humidified atmosphere with 10% CO 2 and routinely tested for mycoplasma contamination. HEK293 cell transfection and co-immunoprecipitation (co-IP) were performed as described in [37] using jetPEI (Polyplus, Graffenstaden, France ) as transfection reagent and Dynabeads TM Protein G Immunoprecipitation Kit (Thermo Scientific, Waltham, MA, USA) for co-IP. For co-IP the following antibodies were used: anti-HA (Covance, MMS-101P, 1:100), anti-myc (Abcam, ab19234, 1:250) and anti-GFP (Abcam, ab290, 1:250).…”

In vivo Functional Genomics for Undiagnosed Patients: The Impact of Small GTPases Signaling Dysregulation at Pan-Embryo Developmental Scale

“…On the other hand, a growing body of data in animal models proves the interplay between RHO and Wnt during embryonic NC migration (reviewed by Mayor and Theveneau, 2013). In this context, Kratzer et al (2020) have recently provided evidence for a novel and a complex modulatory mechanism acting during frog development, where Rho GEF Trio activates Rac1 at the level of cell protrusions of migratory cranial NC via interaction with Dvl, a major player of PCP signaling (Gao and Chen, 2010), similar to other Dvl-dependent mechanisms seen for Rho activation in Xenopus, Drosophila, and zebrafish development (Schlessinger et al, 2009). It is also becoming clear that RAC1 is involved in a positive regulation of canonical Wnt signaling by enabling the nuclear accumulation of β-catenin (Wu et al, 2008;Schlessinger et al, 2009).…”

Decoding Dishevelled-Mediated Wnt Signaling in Vertebrate Early Development

“…As in mice, Dvl function is also required for neural tube closure by regulating CE movements of the midline and coordinating polarity among epithelial cells (Wallingford and Harland, 2002;Seo et al, 2017). In addition, Dvl2-mediated activation of Rac1 through the DEP domain also controls the protrusive activity of neural crest cells during migration (Kratzer et al, 2020). Because cellular polarization is tightly dependent on the asymmetric activation of Wnt/PCP signaling, both reduced and increased levels of Dvl disrupts asymmetric movements.…”