title: Isolation of mutant T lymphocytes with defects in capacitative calcium entry.
abstract: Calcium and calcium-binding proteins play important roles in the signaling cascade leading from the initial engagement of TCRs on T cells to the fully activated state. To undertake a molecular dissection of this cascade, we first isolated a Jurkat T cell line derivative containing the NF-AT promoter element driving transcription of the diphtheria toxin A chain gene (dipA), resulting in rapid cell death. Selecting viable cells that fail to activate NF-AT-dependent transcription, we isolated two independent cell lines possessing defects in capacitative Ca2+ entry. NF-AT-dependent transcription can be restored in these cells by expression of a constitutively active calcineurin, but not overexpression of the Ca2+ regulatory protein CAML, which can normally replace the Ca2+ signal. The defect in these cell lines probably lies between CAML and calcineurin in the T cell activation cascade.
authors.affiliation: Department of Genetics, Stanford University School of Medicine, California 94305, USA.
authors.forename: A T
authors.initials: AT
authors.lastname: Serafini
authors.forename: R S
authors.initials: RS
authors.lastname: Lewis
authors.forename: N A
authors.initials: NA
authors.lastname: Clipstone
authors.forename: R J
authors.initials: RJ
authors.lastname: Bram
authors.forename: C
authors.initials: C
authors.lastname: Fanger
authors.forename: S
authors.initials: S
authors.lastname: Fiering
authors.forename: L A
authors.initials: LA
authors.lastname: Herzenberg
authors.forename: G R
authors.initials: GR
authors.lastname: Crabtree
mesh_terms: D001483:Base Sequence; D019703:Calcineurin; D002118:Calcium / Q000502:physiology*; D002148:Calmodulin-Binding Proteins / Q000502:physiology; D002451:Cell Compartmentation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D009154:Mutation; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010749:Phosphoprotein Phosphatases / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D002148:Calmodulin-Binding Proteins; D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D014157:Transcription Factors; D019703:Calcineurin; D010749:Phosphoprotein Phosphatases; D002118:Calcium