title: ADP-ribosylation factor 6 mediates E-cadherin recovery by chemical chaperones.
abstract: E-cadherin plays a powerful tumor suppressor role. Germline E-cadherin mutations justify 30% of Hereditary Diffuse Gastric Cancer (HDGC) and missense mutations are found in 30% of these families. We found possible to restore in vitro mutant E-cadherin associated to HDGC syndrome by using Chemical Chaperones (CCs). Herein, our aim was to disclose the molecular mechanisms underlying the CCs effects in E-cadherin regulation. Using cells stably expressing WT E-cadherin or two HDGC-associated missense mutations, we show that upon DMSO treatment, not only mutant E-cadherin is restored and stabilized at the plasma membrane (PM), but also Arf6 and PIPKIγ expressions are altered. We show that modulation of Arf6 expression partially mimics the effect of CCs, suggesting that the cellular effects observed upon CCs treatment are mediated by Arf6. Further, we show that E-cadherin expression recovery is specifically linked to Arf6 due to its role on endocytosis and recycling pathways. Finally, we demonstrated that, as DMSO, several others CCs are able to modulate the trafficking machinery through an Arf6 dependent mechanism. Interestingly, the more effective compounds in E-cadherin recovery to PM are those that simultaneously inhibit Arf6 and stimulate PIPKIγ expression and binding to E-cadherin. Here, we present the first evidence of a direct influence of CCs in cellular trafficking machinery and we show that this effect is of crucial importance in the context of juxtamembrane E-cadherin missense mutations associated to HDGC. We propose that this influence should be taken into account when exploring the therapeutic potential of this type of chemicals in genetic diseases associated to protein-misfolding.
authors.affiliation: Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Figueiredo
authors.forename: Joana
authors.initials: J
authors.lastname: Simões-Correia
authors.forename: Ola
authors.initials: O
authors.lastname: Söderberg
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Suriano
authors.forename: Raquel
authors.initials: R
authors.lastname: Seruca
mesh_terms: D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D015820:Cadherins / Q000378:metabolism*; D051177:Catenins / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004705:Endocytosis / Q000187:drug effects; D005089:Exocytosis / Q000187:drug effects; D006801:Humans; D050505:Mutant Proteins / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000378:metabolism; D000095002:Delta Catenin
chemical_list: D000089982:ADP-Ribosylation Factor 6; D015820:Cadherins; D051177:Catenins; D050505:Mutant Proteins; D034741:RNA, Small Interfering; D017853:Phosphotransferases (Alcohol Group Acceptor); D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human; D004121:Dimethyl Sulfoxide; D000095002:Delta Catenin