title: Chemical rescue of cleft palate and midline defects in conditional GSK-3beta mice.
abstract: Glycogen synthase kinase-3beta (GSK-3beta) has integral roles in a variety of biological processes, including development, diabetes, and the progression of Alzheimer's disease. As such, a thorough understanding of GSK-3beta function will have a broad impact on human biology and therapeutics. Because GSK-3beta interacts with many different pathways, its specific developmental roles remain unclear. We have discovered a genetic requirement for GSK-3beta in midline development. Homozygous null mice display cleft palate, incomplete fusion of the ribs at the midline and bifid sternum as well as delayed sternal ossification. Using a chemically regulated allele of GSK-3beta (ref. 6), we have defined requirements for GSK-3beta activity during discrete temporal windows in palatogenesis and skeletogenesis. The rapamycin-dependent allele of GSK-3beta produces GSK-3beta fused to a tag, FRB* (FKBP/rapamycin binding), resulting in a rapidly destabilized chimaeric protein. In the absence of drug, GSK-3beta(FRB)*(/FRB)* mutants appear phenotypically identical to GSK-3beta-/- mutants. In the presence of drug, GSK-3betaFRB* is rapidly stabilized, restoring protein levels and activity. Using this system, mutant phenotypes were rescued by restoring endogenous GSK-3beta activity during two distinct periods in gestation. This technology provides a powerful tool for defining windows of protein function during development.
authors.affiliation: The Department of Pathology, King's College London, London SE1 9RT, UK. karen.liu@kcl.ac.uk
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Liu
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Arron
authors.forename: Kryn
authors.initials: K
authors.lastname: Stankunas
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Crabtree
authors.forename: Michael T
authors.initials: MT
authors.lastname: Longaker
mesh_terms: D000483:Alleles; D000818:Animals; D002972:Cleft Palate / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D051379:Mice; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D020123:Sirolimus / Q000494:pharmacology
chemical_list: C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3; D020123:Sirolimus