Question

Discuss one of the following pathways in detail – both activation and turn off:

• The delta notched path. Also discuss how this path fits into the putative role of various proteases in the flawed handling of APP in Alzheimer patients.
• The sonic hedgehog path
• Discuss the wnt path and how it is involved in the differentiation of colonic epithelia cells. How is the pathway activated, structure and function of the various players and the complexes they form, roles for b-catenin [stimulate stem cells to proliferate, migrating cells to hold onto one another, and terminal differentiated cells to slough]?

Answer 1

Explanation:

Sonic hedgehog path: Hedgehog pathway is a signaling pathway which transmitts the information for proper cell differentiation to embryonic cells. This pathway is one of the key regulators of animal development also in regulating adult stem cells involved in maintenance and regeneration of adult tissues. These hedgehog proteins in all embryo as well as adults. Their malfunction results in diseases like Basal cell carcinoma. Mammals are provided with 3 hedgehog homologues- Desert hedgehog (Dhh), Indian hedgehog (Ihh) and Sonic hedgehog (Shh). The pathway is also involved in development of cancers. Shh functions in embryogenesis. It is carried out in two ways- Canonical and Non canonical pathway.