Caveolin-1 regulates dorsoventral patterning through direct interaction with β-catenin in zebrafish

Abstract

Caveolin-1 (Cav-1) is the principal component of plasma membrane caveolae that negatively regulates a number of cellular signaling events including canonical Wnt signaling. Activation of the Wnt/beta-catenin pathway is essential for dorsal organizer formation and specification in early vertebrate embryos, but it remains not well understood what controls dorsal activity of maternal beta-catenin and how Cav-1 functions in zebrafish embryogenesis. Here, we report that Cav-1 is required for proper dorsoventral patterning in zebrafish. Both Wnt and BMP signals act coordinately to negatively control transcriptional expression of cav-1 during embryonic development. Ectopic expression of Cav-1alpha or -1beta resulted in formation of typical ventralized embryos, whereas Cav-1 knockdown led to abnormal embryos with expanded expression of dorsal genes. Cav-1 overexpression disrupts the nuclear translocation of beta-catenin through the interaction of its scaffolding domain with Cav-1 binding motif of beta-catenin. This reciprocal interaction is necessary for the ventralizing activity of Cav-1. We have further demonstrated that human Cav-1 proteins have conserved ventralizing activity in zebrafish embryogenesis. Thus, maternally expressed zebrafish Cav-1 regulates dorsoventral patterning by limiting nuclear translocation of active beta-catenin.

Crosstalk between Caveolin-1/Extracellular Signal-regulated Kinase (ERK) and β-Catenin Survival Pathways in Osteocyte Mechanotransduction

“…Our current findings suggest that caveolin-1 also interacts with ␤-catenin in osteocytic cells, as expression of caveolin-1 is required for ␤-catenin membrane localization upon mechanical stimulation. Previous evidence has shown that caveolin-1 interacts with ␤-catenin through its scaffolding domain in zebrafish (41).…”

Zebrafish Abcb4 is a potential efflux transporter of microcystin-LR

“…Western blotting of Abcb4 or Abcb4-G1177D proteins in LLC-PK1 cells and subcellular localization detection of Flag-tagged Abcb4 or Abcb4-G1177D in LLC-PK1 cells were performed following our previous protocol (Mo et al, 2010;Wang et al, 2012). Briefly, Abcb4-or Abcb4-G1177D-expressing LLC-PK1 cells were fixed with 4% paraformaldehyde and blocked with PBS containing 10% goat serum for 1 h. Cells were incubated with anti-Flag antibody (1:200, Sigma) for 1 h at room temperature and then with FITC-conjugated secondary antibody (antimouse IgG, 1:1000, Molecular Probes).…”

Molecular characterization and functions of zebrafish ABCC2 in cellular efflux of heavy metals

“…Immunofluorescence staining was performed as described previously (Mo et al, 2010). Briefly, 24 h after transfection, cells were permeabilized in Triton buffer for 3 min at room temperature, blocked for 15 min in a buffer containing 1% BSA and 0.09% sodium azide, and incubated with the primary antibodies (Mouse anti-Flag) at room temperature for 1 h. Cells were then incubated with the secondary Fig.…”