Cadherin-6B undergoes macropinocytosis and clathrin-mediated endocytosis during cranial neural crest cell EMT

Abstract

The epithelial-to-mesenchymal transition (EMT) is important for the formation of migratory neural crest cells during development and is co-opted in human diseases such as cancer metastasis. Chick premigratory cranial neural crest cells lose intercellular contacts, mediated in part by Cadherin-6B (Cad6B), migrate extensively, and later form a variety of adult derivatives. Importantly, modulation of Cad6B is crucial for proper neural crest cell EMT. Although Cad6B possesses a long half-life, it is rapidly lost from premigratory neural crest cell membranes, suggesting the existence of post-translational mechanisms during EMT. We have identified a motif in the Cad6B cytoplasmic tail that enhances Cad6B internalization and reduces the stability of Cad6B upon its mutation. Furthermore, we demonstrate for the first time that Cad6B is removed from premigratory neural crest cells through cell surface internalization events that include clathrin-mediated endocytosis and macropinocytosis. Both of these processes are dependent upon the function of dynamin, and inhibition of Cad6B internalization abrogates neural crest cell EMT and migration. Collectively, our findings reveal the significance of post-translational events in controlling cadherins during neural crest cell EMT and migration.

Cadherin-11 endocytosis through binding to clathrin promotes cadherin-11-mediated migration in prostate cancer cells

“…Gavard and Gutkind (2006) show that stimulation with VEGF promotes the rapid endocytosis of VE-cadherin, resulting in disruption of the endothelial barrier and increased vascular permeability. Recently, Padmanabhan and Taneyhill (2015) have shown that clathrinmediated endocytosis of cadherin-6B plays a role in the neural crest cell epithelial-mesenchymal transition and migration. Thus, the dynamic changes in the surface levels of cadherin molecules through clathrin-mediated endocytosis affect cadherin-mediated adhesion and migratory activities.…”

“…Although E-Cad, which plays a role in maintaining cell polarity (Nelson et al, 2013), has been found to be downregulated in cancers, aberrant overexpression of mesenchymal cadherins, including N-cadherin (N-Cad; also known as CDH2) and Cad11 (Kosalková et al, 2015;Padmanabhan and Taneyhill, 2015;Tamura et al, 2008), are observed in some cancers. Such a cadherin switch has been shown to occur during the progression of prostate (Chu et al, 2008;Huang et al, 2010;Lee et al, 2010), breast (Tamura et al, 2008) and pancreatic (MartinezContreras et al, 2015;Xiumin et al, 2015) cancers.…”

Should I stay or should I go? Cadherin function and regulation in the neural crest

“…In vivo evidence for this process during EMT, however, was lacking, until recent experiments revealed the internalization of membrane Cadherin-6B during chick cranial neural crest cell EMT (Padmanabhan & Taneyhill, 2015). Using Na1K1 ATPase as a proxy for early endosomes, this group demonstrated the presence of Cadherin-6B-positive cytoplasmic, endocytic puncta in a stable cell line expressing Cadherin-6B and in neural crest cells undergoing EMT and emigrating, both in in vivo and ex vivo explants.…”

“…Consequently, inhibitor treatment also led to a loss of neural crest cell EMT. Moreover, both of these internalization processes are dynamin-dependent, as macropinosomes and membrane-bound vesicles accumulate in explanted neural crest cells treated with a dynamin-inhibitor, along with a concomitant reduction in EMT and migration (Padmanabhan and Taneyhill, 2015). …”

Cellular organization and boundary formation in craniofacial development

“…Tspan18 is repressed by FoxD3, to alleviate stabilization of cadherin‐6B during EMT enabling subsequent NCC migration (Fairchild & Gammill, ). In premigratory NCCs clatherin‐mediated endocytosis and macropinocytosis also remove cadherin‐6B from the cell surface (Padmanabhan & Taneyhill, ). Cadherin‐6B down regulation is directly transcriptionally controlled both by direct suppression by the Snail2 transcription factor, and post‐translationally by proteolytic cleavage by ADAM metalloproteases ADAM 10 and 19; depletion of these metalloproteases leads to the extended maintenance of cadherin‐6B in the premigratory NCCs (Schiffmacher, Padmanabhan, Jhingory, & Taneyhill, ; Schiffmacher, Xie, & Taneyhill, ; Strobl‐Mazzulla & Bronner, ; Taneyhill, Coles, & Bronner‐Fraser, ).…”