TY - JOUR
T1 - Phosphorylation-independent membrane relocalization of ezrin following association with Dbl in vivo
AU - Vanni, Cristina
AU - Parodi, Alessia
AU - Mancini, Patrizia
AU - Visco, Vincenzo
AU - Ottaviano, Catherine
AU - Torrisi, Maria Rosaria
AU - Eva, Alessandra
PY - 2004/5/20
Y1 - 2004/5/20
N2 - Ezrin, a widespread protein involved in cell migration, morphogenesis and cell adhesion, belongs to a large family of proteins known as ERM (ezrin, radixin, moesin). These three closely related proteins are thought to function as linkers between plasma membrane and actin cytoskeleton and their function is regulated by the small GTP-binding protein Rho. It has been previously shown that the active form of radixin can bind in vitro to Dbl, a Rho-specific guanine nucleotide exchange factor, although an in vivo interaction has not yet been demonstrated. In this paper, we attempted to investigate whether ezrin can also associate with Dbl. We show here that Dbl protein can effectively bind both in vitro and in vivo to the N-terminal region (amino acids 1-531) of a constitutively active mutant of ezrin and with the full-length molecule. We found that this binding is mediated by the Dbl pleckstrin homology domain, responsible for the proper subcellular localization of the Dbl protein. Moreover, we show that Dbl induces localization to the plasma membrane of both the active deletion mutant and the full-length ezrin proteins. Finally, we show that the relocalization of ezrin is independent of Dbl GEF activity. These results indicate that Dbl could induce translocation of ezrin to the plasma membrane through a mechanism that does not require ezrin C-terminus phosphorylation by Rho-associated kinases.
AB - Ezrin, a widespread protein involved in cell migration, morphogenesis and cell adhesion, belongs to a large family of proteins known as ERM (ezrin, radixin, moesin). These three closely related proteins are thought to function as linkers between plasma membrane and actin cytoskeleton and their function is regulated by the small GTP-binding protein Rho. It has been previously shown that the active form of radixin can bind in vitro to Dbl, a Rho-specific guanine nucleotide exchange factor, although an in vivo interaction has not yet been demonstrated. In this paper, we attempted to investigate whether ezrin can also associate with Dbl. We show here that Dbl protein can effectively bind both in vitro and in vivo to the N-terminal region (amino acids 1-531) of a constitutively active mutant of ezrin and with the full-length molecule. We found that this binding is mediated by the Dbl pleckstrin homology domain, responsible for the proper subcellular localization of the Dbl protein. Moreover, we show that Dbl induces localization to the plasma membrane of both the active deletion mutant and the full-length ezrin proteins. Finally, we show that the relocalization of ezrin is independent of Dbl GEF activity. These results indicate that Dbl could induce translocation of ezrin to the plasma membrane through a mechanism that does not require ezrin C-terminus phosphorylation by Rho-associated kinases.
KW - Dbl oncogene
KW - ERM
KW - PH domain
UR - http://www.scopus.com/inward/record.url?scp=2942535830&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=2942535830&partnerID=8YFLogxK
U2 - 10.1038/sj.onc.1207509
DO - 10.1038/sj.onc.1207509
M3 - Article
C2 - 15064738
AN - SCOPUS:2942535830
VL - 23
SP - 4098
EP - 4106
JO - Oncogene
JF - Oncogene
SN - 0950-9232
IS - 23
ER -