Characterization of the constitutive and inducible components of a T cell IL-4 activation responsive element.
An Il-4 regulatory element, activation responsive element (ARE), located between -88 and -60, contributes to activation-dependent transcription of IL-4/CAT reporter gene constructs in T cells. It was previously demonstrated that nuclear proteins present in both unstimulated and stimulated T cells specifically interact with the ARE. In this study, these proteins were further characterized. UV cross-linking experiments established that multiple proteins are associated with the ARE in both the constitutive and activation-dependent complexes and several of these have identical apparent m.w. The formation of both complexes is dependent on the same ARE subsequence. In addition, activator protein 1 family members are uniquely associated with the activation-dependent complex. These results support a model in which activation-dependent proteins, including jun/fos family members, associate with a preexisting transcription complex to influence inducible IL-4 gene transcription. The ARE shares 9 bp of sequence identity with the IL-2 nuclear factor of activated T cell (NF-AT) binding site within the critical protein binding region, and several features of ARE-protein interactions are similar to the NF-AT transcription complex. However, we demonstrate that the constitutive nuclear ARE-associated factors react with Abs, raised to NF-ATp and NF-ATc, preferentially bind to the ARE but not to the NF-AT binding site and are cyclosporin A sensitive. Taken together, these data indicate that there are IL-4 gene-specific factors associated with the ARE and that the formation of the ARE and NF-AT complexes are regulated differently.
Tara
D
D
Department of Medicine, Oregon Health Sciences University, Portland 97201, USA.
Weiss
D L
DL
Brown
M A
MA
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000032:analysis; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000502:physiology; D004586:Electrophoresis / Q000379:methods; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*; D014157:Transcription Factors / Q000502:physiology; D014162:Transfection / Q000235:genetics; D014466:Ultraviolet Rays
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D015847:Interleukin-4; D015500:Chloramphenicol O-Acetyltransferase