TY - JOUR
T1 - Myristoylated Naked2 antagonizes Wnt-β-catenin activity by degrading dishevelled-1 at the plasma membrane
AU - Hu, Tianhui
AU - Li, Cunxi
AU - Cao, Zheng
AU - Van Raay, Terence J.
AU - Smith, Jason G.
AU - Willert, Karl
AU - Solnica-Krezel, Lila
AU - Coffey, Robert J.
PY - 2010/4/30
Y1 - 2010/4/30
N2 - In Drosophila, naked cuticle is an inducible antagonist of the Wnt-β-catenin pathway, likely acting at the level of Dishevelled (Dsh/Dvl), an essential component of this pathway. The mechanism by which naked cuticle and its two vertebrate orthologs, Naked1 (NKD1) and Naked2 (NKD2), inhibit Dvl function is unknown. NKD2 is myristoylated, a co-translational modification that leads to its plasma membrane localization. In contrast, myristoylation- deficient G2A NKD2 is cytoplasmic. Here in we show that the ability of Nkd2/NKD2 to antagonize Wnt-β-catenin activity during zebrafish embryonic development and in mammalian HEK293 cells is myristoylation-dependent. NKD2 and Dvl-1 interact and co-localize at the lateral membrane of polarized epithelial cells. In reciprocal overexpression and siRNA knockdown experiments, NKD2and Dvl-1 destabilize each other via enhanced polyubiquitylation; this effect is also dependent upon Naked2 myristoylation. Cell fractionation and ubiquitylation assays indicate that endogenous NKD2 interacts with a slower migrating, ubiquitylated form of Dvl-1 in plasma membrane fractions. These results provide a mechanism by which NKD2 antagonizes Wnt signaling: myristoylated NKD2 interacts with Dvl-1 at the plasma membrane, and this interaction leads to their mutual ubiquitin-mediated proteasomal degradation.
AB - In Drosophila, naked cuticle is an inducible antagonist of the Wnt-β-catenin pathway, likely acting at the level of Dishevelled (Dsh/Dvl), an essential component of this pathway. The mechanism by which naked cuticle and its two vertebrate orthologs, Naked1 (NKD1) and Naked2 (NKD2), inhibit Dvl function is unknown. NKD2 is myristoylated, a co-translational modification that leads to its plasma membrane localization. In contrast, myristoylation- deficient G2A NKD2 is cytoplasmic. Here in we show that the ability of Nkd2/NKD2 to antagonize Wnt-β-catenin activity during zebrafish embryonic development and in mammalian HEK293 cells is myristoylation-dependent. NKD2 and Dvl-1 interact and co-localize at the lateral membrane of polarized epithelial cells. In reciprocal overexpression and siRNA knockdown experiments, NKD2and Dvl-1 destabilize each other via enhanced polyubiquitylation; this effect is also dependent upon Naked2 myristoylation. Cell fractionation and ubiquitylation assays indicate that endogenous NKD2 interacts with a slower migrating, ubiquitylated form of Dvl-1 in plasma membrane fractions. These results provide a mechanism by which NKD2 antagonizes Wnt signaling: myristoylated NKD2 interacts with Dvl-1 at the plasma membrane, and this interaction leads to their mutual ubiquitin-mediated proteasomal degradation.
UR - http://www.scopus.com/inward/record.url?scp=77951548367&partnerID=8YFLogxK
U2 - 10.1074/jbc.M109.075945
DO - 10.1074/jbc.M109.075945
M3 - Article
C2 - 20177058
AN - SCOPUS:77951548367
VL - 285
SP - 13561
EP - 13568
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 18
ER -