| Description: |
Noggin is a secreted homodimeric glycoprotein featuring a cystine-knot topology akin to BMPs. It binds to heparin-containing proteoglycans near the cell surface, inhibiting TGF-β signal transduction by blocking TGF-β family ligands from binding to their receptors. Noggin plays a crucial role in neural induction by specifically inhibiting BMP4, alongside other TGF-β signaling inhibitors like chordin and follistatin.
Mouse knockout studies have highlighted Noggin's critical involvement in bone development, joint formation, and neural tube fusion during embryogenesis. It antagonizes specific BMPs at key developmental stages, such as during neural tube, somite, and cardiomyocyte growth and patterning. In skeletal development, Noggin prevents chondrocyte hyperplasia, ensuring proper joint formation.
In culture settings involving human embryonic stem cells (hESC) or neural stem cells, Noggin addition antagonizes BMP activity, enabling stem cells to proliferate while maintaining their undifferentiated state. Alternatively, it supports differentiation into dopaminergic neurons. Moreover, Noggin is essential for maintaining adult stem cell populations in vivo, such as neural stem cells in the hippocampus. |
