| Modification Notes |
The Wnt genes, a group of well-conserved, cysteine-rich, secreted glycoproteins, are required for numerous developmental processes, including embryogenesis, asymmetric cell division and central nervous system (CNS) patterning. The association of the Wnt protein with the seven membrane spanning receptor frizzled activates dishevelled, which downregulates glycogen synthase kinase (GSK) through serine phosphorylation. Reduced levels of active GSK results in the accumulation of b-catenin and subsequent regulation of developmentally significant Wnt target genes. Wnt antagonists, which include Dickkopf (Dkk1-4), Soggy-1 (also designated DkkL1), frizzled-related protein (sFRP) and Wnt inhibitory factor-1 (WIF-1), are necessary to ensure normal spatial and temporal patterns of Wnt activity during developmental processes. Soggy-1 is a secreted antagonist of Wnt expressed in preimplantation mouse embryos and developing neural tissue, as well as adult testis tissue. Soggy-1 is subjected to posttranslational modification by glycosylation; additional modifications have been observed and are yet to be characterized. The molecular weight of Soggy-1 has been observed to vary depending on tissue and cell type. |
