Selective inhibition of NFAT activation by a peptide spanning the calcineurin targeting site of NFAT.
NFAT transcription factors play a key role in the immune response. The activation of NFAT proteins is controlled by calcineurin, the calmodulin-dependent phosphatase that is inhibited by the immunosuppressive drugs cyclosporin A and FK506. Here we identify a short conserved sequence in NFAT proteins that targets calcineurin to NFAT. Mutation of a single residue in this sequence impairs the calcineurin-mediated dephosphorylation and nuclear translocation of NFAT1. Peptides spanning the region inhibit the ability of calcineurin to bind to and dephosphorylate NFAT proteins, without affecting the phosphatase activity of calcineurin against other substrates. When expressed intracellularly, a corresponding peptide inhibits NFAT dephosphorylation, nuclear translocation, and NFAT-mediated expression in response to stimulation. Thus, disruption of the enzyme-substrate docking interaction that directs calcineurin to NFAT can effectively block NFAT-dependent functions.
Aramburu
J
J
Center for Blood Research, Harvard Medical School, Boston Massachusetts 02115, USA.
Garcia-Cózar
F
F
Raghavan
A
A
Okamura
H
H
Rao
A
A
Hogan
P G
PG
D000595:Amino Acid Sequence; D001665:Binding Sites / Q000502:physiology; D019703:Calcineurin / Q000378:metabolism*; D002467:Cell Nucleus / Q000737:chemistry / Q000201:enzymology; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D016296:Mutagenesis / Q000502:physiology; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D021382:Protein Sorting Signals / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D050778:NFATC Transcription Factors; C494006:NFATC2 protein, human; C494008:NFATC3 protein, human; C494010:NFATC4 protein, human; D009687:Nuclear Proteins; D010750:Phosphoproteins; D021382:Protein Sorting Signals; D014157:Transcription Factors; D049452:Green Fluorescent Proteins; D019703:Calcineurin