The Significance of Tetramerization in Promoter Recruitment by Stat5

ABSTRACT Stat5a and Stat5b are rapidly activated by a wide range of cytokines and growth factors, including interleukin-2 (IL-2). We have previously shown that these signal transducers and activators of transcription (STAT proteins) are key regulatory proteins that bind to two tandem gamma interferon-activated site (GAS) motifs within an IL-2 response element (positive regulatory region III [PRRIII]) in the human IL-2Rα promoter. In this study, we demonstrate cooperative binding of Stat5 to PRRIII and explore the molecular basis underlying this cooperativity. We demonstrate that formation of a tetrameric Stat5 complex is essential for the IL-2-inducible activation of PRRIII. Stable tetramer formation of Stat5 is mediated through protein-protein interactions involving a tryptophan residue conserved in all STATs and a lysine residue in the Stat5 N-terminal domain (N domain). The functional importance of tetramer formation is shown by the decreased levels of transcriptional activation associated with mutations in these residues. Moreover, the requirement for STAT protein-protein interactions for gene activation from a promoter with tandemly linked GAS motifs can be relieved by strengthening the avidity of protein-DNA interactions for the individual binding sites. Taken together, these studies demonstrate that a dimeric but tetramerization-deficient Stat5 protein can activate only a subset of target sites. For functional activity on a wider range of potential recognition sites, N-domain-mediated oligomerization is essential.

[1]  W. Leonard,et al.  Stat5b Is Essential for Natural Killer Cell–mediated Proliferation and Cytolytic Activity , 1998, The Journal of experimental medicine.

[2]  W. Leonard,et al.  Delineation of the regions of interleukin-2 (IL-2) receptor beta chain important for association of Jak1 and Jak3. Jak1-independent functional recruitment of Jak3 to Il-2Rbeta. , 1998, The Journal of biological chemistry.

[3]  W. Leonard,et al.  Delineation of the Regions of Interleukin-2 (IL-2) Receptor β Chain Important for Association of Jak1 and Jak3 , 1998, The Journal of Biological Chemistry.

[4]  J. Darnell,et al.  Structure of the amino-terminal protein interaction domain of STAT-4. , 1998, Science.

[5]  U. Schindler,et al.  Interaction of STAT5 Dimers on Two Low Affinity Binding Sites Mediates Interleukin 2 (IL-2) Stimulation of IL-2 Receptor α Gene Transcription* , 1997, The Journal of Biological Chemistry.

[6]  W. Leonard,et al.  Signaling from the IL-2 receptor to the nucleus. , 1997, Cytokine & growth factor reviews.

[7]  W. Leonard,et al.  An indirect effect of Stat5a in IL-2-induced proliferation: a critical role for Stat5a in IL-2-mediated IL-2 receptor alpha chain induction. , 1997, Immunity.

[8]  J. Darnell.  STATs and gene regulation. , 1997, Science.

[9]  J. Darnell,et al.  The state of the STATs: recent developments in the study of signal transduction to the nucleus. , 1997, Current opinion in cell biology.

[10]  P. Bucher,et al.  Elf-1 and Stat5 bind to a critical element in a new enhancer of the human interleukin-2 receptor alpha gene , 1997, Molecular and cellular biology.

[11]  T. Decker,et al.  GAS elements: a few nucleotides with a major impact on cytokine-induced gene expression. , 1997, Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research.

[12]  R. Nussinov,et al.  Protein binding versus protein folding: the role of hydrophilic bridges in protein associations. , 1997, Journal of molecular biology.

[13]  P. Bucher,et al.  Elf-1 and Stat5 bind to a critical element in a new enhancer of the human interleukin-2 receptor alpha gene , 1996, Molecular and cellular biology.

[14]  B. Chait,et al.  DNA binding of in vitro activated Stat1 alpha, Stat1 beta and truncated Stat1: interaction between NH2‐terminal domains stabilizes binding of two dimers to tandem DNA sites. , 1996, The EMBO journal.

[15]  W. Leonard,et al.  An IL‐2 response element in the human IL‐2 receptor alpha chain promoter is a composite element that binds Stat5, Elf‐1, HMG‐I(Y) and a GATA family protein. , 1996, The EMBO journal.

[16]  U. Schindler,et al.  Requirements for interleukin-4-induced gene expression and functional characterization of Stat6 , 1996, Molecular and cellular biology.

[17]  T. Hoey,et al.  Cooperative DNA Binding and Sequence-Selective Recognition Conferred by the STAT Amino-Terminal Domain , 1996, Science.

[18]  Claude Desplan,et al.  Identification of a Stat Gene That Functions in Drosophila Development , 1996, Cell.

[19]  J. Ihle.  STATs: Signal Transducers and Activators of Transcription , 1996, Cell.

[20]  N. Reich,et al.  Interleukin 2 activates STAT5 transcription factor (mammary gland factor) and specific gene expression in T lymphocytes. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[21]  B. Groner,et al.  Signaling through the interleukin 2 receptor beta chain activates a STAT-5-like DNA-binding activity. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[22]  B. Groner,et al.  Activation of Stat5 by interleukin 2 requires a carboxyl-terminal region of the interleukin 2 receptor beta chain but is not essential for the proliferative signal transmission. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[23]  S. McKnight,et al.  Components of a Stat recognition code: evidence for two layers of molecular selectivity. , 1995, Immunity.

[24]  A. Miyajima,et al.  Interleukin 2 and erythropoietin activate STAT5/MGF via distinct pathways. , 1995, The EMBO journal.

[25]  P. Bucher,et al.  Mouse interleukin-2 receptor alpha gene expression. Interleukin-1 and interleukin-2 control transcription via distinct cis-acting elements. , 1995, The Journal of biological chemistry.

[26]  J. Darnell,et al.  A STAT protein domain that determines DNA sequence recognition suggests a novel DNA-binding domain. , 1995, Genes & development.

[27]  S. McKnight,et al.  Identification and purification of human Stat proteins activated in response to interleukin-2. , 1995, Immunity.

[28]  W. Leonard,et al.  The role of shared receptor motifs and common Stat proteins in the generation of cytokine pleiotropy and redundancy by IL-2, IL-4, IL-7, IL-13, and IL-15. , 1995, Immunity.

[29]  J. Darnell,et al.  Spacing of palindromic half sites as a determinant of selective STAT (signal transducers and activators of transcription) DNA binding and transcriptional activity. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[30]  I. Kerr,et al.  Activation of JAK kinases and STAT proteins by interleukin‐2 and interferon alpha, but not the T cell antigen receptor, in human T lymphocytes. , 1994, The EMBO journal.

[31]  A. Svejgaard,et al.  Interleukin‐2 induces tyrosine phosphorylation and nuclear translocation of stat3 in human T lymphocytes , 1994, European journal of immunology.

[32]  J. Johnston,et al.  Interaction of IL-2R beta and gamma c chains with Jak1 and Jak3: implications for XSCID and XCID. , 1994, Science.

[33]  O. Silvennoinen,et al.  Functional activation of Jak1 and Jak3 by selective association with IL-2 receptor subunits. , 1994, Science.

[34]  J. Gribben,et al.  Prevention of T cell anergy by signaling through the gamma c chain of the IL-2 receptor. , 1994, Science.

[35]  E. Liu,et al.  Involvement of the Jak-3 Janus kinase in signalling by interleukins 2 and 4 in lymphoid and myeloid cells , 1994, Nature.

[36]  J. Johnston,et al.  Phosphorylation and activation of the Jak-3 Janus kinase in response to interleukin-2 , 1994, Nature.

[37]  M. Erdos,et al.  Heterodimerization of the IL-2 receptor β- and γ-chain cytoplasmic domains is required for signalling , 1994, Nature.

[38]  W. Leonard,et al.  Jaks and STATs: biological implications. , 1998, Annual review of immunology.

[39]  W. Leonard,et al.  Cloning of Human Stat5B RECONSTITUTION OF INTERLEUKIN-2-INDUCED Stat5A AND Stat5B DNA BINDING ACTIVITY IN COS-7 CELLS* , 1996 .

[40]  H. Fujii.  Activation of Stat5 by interleukin 2 requires a carboxy-terminal region β chain but is not exxential for the proliferative signal transdution. , 1995 .