CSB328H1 Lecture Notes - Lecture 7: Gsk-3, Catenin, Flatworm
Document Summary
D. lacteum has the ability to make heads but it is prevented by - catenin. Major signalling pathway in all animals: wnt binds to the transmembrane receptor frizzled (which is in complex with lrp5/6, this activates disheveled (intracellularly, the destruction complex (axin, apc, gsk3, -catenin) binds to dishevelled. This causes the destruction complex to be shut down: -catenin released and sent to the nucleus, there -catenin binds with tcf, -catenin + tcf binds to dna initiating transcription. In the absence of wnt, gsk3 in the destruction complex phosphorylates. Catenin, targeting it for degradation summary: disheveled inhibits gsk3 and gsk3 inhibits -catenin. -in s. mediterranea (flat worm with wonderful regeneration abilities) If you amputate the tail, the head fragment reforms the tail. If you amputate the tail and treat the head fragment with wnt or - catenin dsrna the posterior blastema forms a head. Knockout wnt or -catenin then the worm will make a head.
