Critical Role of STAT5 transcription factor tetramerization for cytokine responses and normal immune function.
Immunity
; 36(4): 586-99, 2012 Apr 20.
Article
em En
| MEDLINE
| ID: mdl-22520852
ABSTRACT
Cytokine-activated STAT proteins dimerize and bind to high-affinity motifs, and N-terminal domain-mediated oligomerization of dimers allows tetramer formation and binding to low-affinity tandem motifs, but the functions of dimers versus tetramers are unknown. We generated Stat5a-Stat5b double knockin (DKI) N-domain mutant mice in which STAT5 proteins form dimers but not tetramers, identified cytokine-regulated genes whose expression required STAT5 tetramers, and defined dimer versus tetramer consensus motifs. Whereas Stat5-deficient mice exhibited perinatal lethality, DKI mice were viable; thus, STAT5 dimers were sufficient for survival. Nevertheless, STAT5 DKI mice had fewer CD4(+)CD25(+) T cells, NK cells, and CD8(+) T cells, with impaired cytokine-induced and homeostatic proliferation of CD8(+) T cells. Moreover, DKI CD8(+) T cell proliferation after viral infection was diminished and DKI Treg cells did not efficiently control colitis. Thus, tetramerization of STAT5 is critical for cytokine responses and normal immune function, establishing a critical role for STAT5 tetramerization in vivo.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
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Citocinas
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Linfócitos T CD8-Positivos
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Fator de Transcrição STAT5
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article