Isolation of mutant T lymphocytes with defects in capacitative calcium entry.
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.
Serafini
A T
AT
Department of Genetics, Stanford University School of Medicine, California 94305, USA.
Lewis
R S
RS
Clipstone
N A
NA
Bram
R J
RJ
Fanger
C
C
Fiering
S
S
Herzenberg
L A
LA
Crabtree
G R
GR
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
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