title: Creation and characterization of BAC-transgenic mice with physiological overexpression of epitope-tagged RCAN1 (DSCR1).
abstract: The chromosome 21 gene RCAN1, encoding a modulator of the calcineurin (CaN) phosphatase, is a candidate gene for contributing to cognitive disability in people with Down syndrome (DS; trisomy 21). To develop a physiologically relevant model for studying the biochemistry of RCAN1 and its contribution to DS, we generated bacterial artificial chromosome-transgenic (BAC-Tg) mouse lines containing the human RCAN1 gene with a C-terminal HA-FLAG epitope tag incorporated by recombineering. The BAC-Tg was expressed at levels only moderately higher than the native Rcan1 gene: approximately 1.5-fold in RCAN1                 (BAC-Tg1) and twofold in RCAN1                 (BAC-Tg2). Affinity purification of the RCAN1 protein complex from brains of these mice revealed a core complex of RCAN1 with CaN, glycogen synthase kinase 3-beta (Gsk3b), and calmodulin, with substoichiometric components, including LOC73419. The BAC-Tg mice are fully viable, but long-term synaptic potentiation is impaired in proportion to BAC-Tg dosage in hippocampal brain slices from these mice. RCAN1 can act as a tumor suppressor in some systems, but we found that the RCAN1 BAC-Tg did not reduce mammary cancer growth when present at a low copy number in Tp53;WAP-Cre mice. This work establishes a useful mouse model for investigating the biochemistry and dose-dependent functions of the RCAN1 protein in vivo.
authors.affiliation: Institute for Cancer Genetics, Columbia University Medical Center, Herbert Irving Cancer Research Building, New York, NY 10032, USA.
authors.forename: Luzhou
authors.initials: L
authors.lastname: Xing
authors.forename: Martha
authors.initials: M
authors.lastname: Salas
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Julia
authors.initials: J
authors.lastname: Gittler
authors.forename: Thomas
authors.initials: T
authors.lastname: Ludwig
authors.forename: Chyuan-Sheng
authors.initials: CS
authors.lastname: Lin
authors.forename: Vundavalli V
authors.initials: VV
authors.lastname: Murty
authors.forename: Wayne
authors.initials: W
authors.lastname: Silverman
authors.forename: Ottavio
authors.initials: O
authors.lastname: Arancio
authors.forename: Benjamin
authors.initials: B
authors.lastname: Tycko
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D019703:Calcineurin / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002875:Chromosomes / Q000235:genetics; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics*; D004268:DNA-Binding Proteins; D004195:Disease Models, Animal; D004314:Down Syndrome / Q000235:genetics; D005260:Female; D018628:Gene Dosage; D005786:Gene Expression Regulation; D056426:Genetic Loci; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D019169:Jurkat Cells; D053208:Kaplan-Meier Estimate; D017774:Long-Term Potentiation / Q000235:genetics; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009124:Muscle Proteins; C108612:RCAN1 protein, human; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3; D019703:Calcineurin