1: J Biol Chem. 2002 May 17;277(20):17821-9. Epub 2002 Feb 20. Enhanced apoptosis of B and T lymphocytes in TAFII105 dominant-negative transgenic mice is linked to nuclear factor-kappa B. Silkov A, Wolstein O, Shachar I, Dikstein R. Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel. The general transcription factor TFIID is composed of the TATA-binding protein (TBP) and 12-14 TBP-associated factors (TAF(II)s). Some TAF(II)s act as bridges between transcription activators and the general transcription machinery through direct interaction with activation domains. Although TAF-mediated transcription activation has been established, there is little genetic evidence connecting it to binding of an activator. TAF(II)105 is a substoichiometric subunit of transcription factor IID highly expressed in B lymphocytes. In this study, we examined the physiological role of TAF(II)105 and its mechanism of action in vivo by expressing two forms of dominant-negative mutant TAF(II)105 in mice. We show that TAF(II)105 has a pro-survival role in B and T lymphocytes, where the native protein is expressed. In addition, TAF(II)105 is important for T cell maturation and for production of certain antibody isotypes. These phenotypic alterations were absent in mice expressing a dominant-negative mutant that lacks one of the domains mediating p65/RelA binding in vitro. These findings provide support to the notion that interaction between the activator and TAF is important for their function in vivo. PMID: 11856754 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 2: J Biol Chem. 2001 Jul 20;276(29):27203-6. Epub 2001 May 22. Invariant chain induces B cell maturation by activating a TAF(II)105-NF-kappaB-dependent transcription program. Matza D, Wolstein O, Dikstein R, Shachar I. Departments of Immunology and Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel. Early stages of B cell development occur in the bone marrow, resulting in formation of immature B cells. From there these immature cells migrate to the spleen where they differentiate to mature cells. This final maturation step is crucial for the B cells to become responsive to antigens and to participate in the immune response. Recently, invariant chain (Ii), a major histocompatibility complex class II chaperone, as well as the transcription factors c-Rel and p65/RelA, were found to play a role in the final antigen-independent differentiation stage of B cells in the spleen. In this study, we investigated a possible link between Ii-dependent B cell maturation and the NF-kappaB pathway. Our studies indicate that Ii-induced B cell maturation involves activation of transcription mediated by the NF-kappaB p65/RelA homodimer and requires the B cell-enriched coactivator TBP-associated factor (II)105. PMID: 11371575 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 3: J Biol Chem. 2000 Sep 8;275(36):27858-64. A constitutive active MEK --> ERK pathway negatively regulates NF-kappa B-dependent gene expression by modulating TATA-binding protein phosphorylation. Carter AB, Hunninghake GW. University of Iowa College of Medicine and the Iowa City Veterans Administration Medical Center, Iowa City, Iowa 52242, USA. aaron-carter@uiowa.edu Endotoxin-induced cytokine gene expression is regulated, in part, by NF-kappaB. We have shown that both the ERK and p38 mitogen-activated protein (MAP) kinases are necessary for cytokine gene transcription and that the p38 MAP kinase is required for NF-kappaB-driven transcription, so we hypothesized that the MEK --> ERK pathway regulated NF-kappaB-driven transcription as well. We found that a constitutive active MEK --> ERK pathway inhibited NF-kappaB-driven transcription. In addition, both PD 98059 and a dominant negative ERK2 augmented NF-kappaB-driven transcription; however, neither PD 98059 nor MEK1 altered NF-kappaB activation at any level. The constitutive active MEK --> ERK pathway inhibited the phosphorylation of TBP, which is necessary for both interaction with RelA and binding to the TATA box. Due to the fact that we have shown that the p38 MAP kinase modulates TBP activation, we evaluated the effect of the constitutive active MEK --> ERK pathway on p38 MAP kinase activity. We found that the MEK --> ERK pathway negatively regulates NF-kappaB-driven transcription, in part, by inhibiting p38 MAP kinase activity. Thus, the ERK and p38 MAP kinases have differential effects on NF-kappaB-driven transcription. PMID: 10878013 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 4: Mol Cell Biol. 1998 Jun;18(6):3234-44. Involvement of TFIID and USA components in transcriptional activation of the human immunodeficiency virus promoter by NF-kappaB and Sp1. Guermah M, Malik S, Roeder RG. Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10021, USA. The purified Rel/NF-kappaB (p50/p65) complex and Sp1 markedly activate transcription from the human immunodeficiency virus type 1 (HIV-1) promoter in a highly purified HeLa reconstituted transcription system. Transcriptional activation by NF-kappaB and Sp1 requires both TFIID and the USA fraction. The USA-derived coactivators PC2 and PC4 fully reconstitute the USA coactivator activity, both by repressing the basal level of transcription and by potentiating activator function to yield large increases in the levels of transcription induction. Under limiting concentrations, PC2 and PC4 also show synergistic effects. The C-terminal portion (amino acids 416 to 550) of the p65 subunit of NF-kappaB is a potent activator when assayed as a Gal fusion in the reconstituted transcription system and interacts both with TATA-binding protein (TBP) and with several human TBP-associated factors (TAFs) that include TAFII250. The p65 activation domain mediates transcription activation in the presence of partially reconstituted TFIID species that include a minimal complex containing only TBP and TAFII250. These studies also show that, like USA components, TAFs can serve both to repress TBP-mediated transcription and, following activator interactions, to reverse the repression and effect a net increase in activity. Taken together, these data underscore the importance of both TAFs and specific USA-derived coactivators for optimal activation of the HIV-1 promoter, as well as certain parallels in their overall mechanisms of action. PMID: 9584164 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 5: J Virol. 1997 Mar;71(3):2004-12. Distinct domains of adenovirus E1A interact with specific cellular factors to differentially modulate human immunodeficiency virus transcription. Parker SF, Felzien LK, Perkins ND, Imperiale MJ, Nabel GJ. Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0650, USA. Transcription of human immunodeficiency virus (HIV) type 1 and other viruses is regulated by the transcription factor NF-kappaB, which interacts with the multifunctional cellular protein p300. p300, originally identified by its ability to bind adenovirus early region 1A (E1A), has also been shown to regulate HIV transcription through its interaction with NF-kappaB. The 13S form of E1A activates HIV gene expression, while the 12S form represses its transcription. In this report, we have investigated whether these divergent effects of E1A are dependent upon common or distinct cellular cofactors, including p300, pRb, and the TATA box-binding protein (TBP). Unlike activation in the absence of E1A, cooperative stimulation of HIV gene expression by 13S E1A and RelA was independent of the ability of E1A to bind p300 but was critically dependent on the E1A CR3 region which associates with TBP. In contrast, inhibition of basal HIV gene expression by the 12S form of E1A was dependent on p300 but not pRb or TBP. Interestingly, mutation of the CR2 region of 12S E1A responsible for pRb binding abolished the repression of HIV transcription stimulated by tumor necrosis factor alpha, suggesting that repression of cytokine-activated transcription involves cofactors different from those used in unstimulated cells. Repression and activation of HIV transcription by different forms of E1A are mediated by distinct sets of cellular cofactors. These findings suggest that E1A has evolved to interact by alternative mechanisms with a transcriptional coactivator and its associated cofactors to differentially modulate cellular and viral gene expression. PMID: 9032332 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 6: Nucleic Acids Res. 1997 Mar 1;25(5):1050-5. Basal transcription factors TBP and TFIIB and the viral coactivator E1A 13S bind with distinct affinities and kinetics to the transactivation domain of NF-kappaB p65. Paal K, Baeuerle PA, Schmitz ML. Institute of Biochemistry and Molecular Biology, Albert-Ludwigs University, Hermann-Herder Strasse 7, D-79104 Freiburg, Germany. Transactivation domains (TADs) are able to contact several components of the basal transcription apparatus and co-activator molecules. In order to study these interactions in biophysical detail, binding of the well-characterized TAD from the human transcription factor NF-kappaB p65 (RelA) to the basal transcription factors TBP and TFIIB and the viral co-activator protein E1A 13S was chosen as a model system to investigate the kinetics and affinities of such protein-protein interactions by surface plasmon resonance analysis. The TAD of NF-kappaB p65 showed remarkably different affinities and kinetics in binding to the various proteins. The real-time kinetic measurements revealed an association rate constant (kass) of 2.3 x 10(6)/M/s for the interaction between the p65 TAD and TBP. The association rate constants of the p65 TAD were much weaker for TFIIB (6.8 x 10(4)/M/s) and for the E1A 13S protein (4.9 x 10(4)/M/s). The dissociation rate constants (kdiss) were determined to be 7.9 x 10(-4)/s for TBP, 1.6 x 10(-3)/s for TFIIB and 1.3 x 10(-3)/s for the E1A protein. Accordingly, the calculated dissociation constants (Kd) differed between 3.4 x 10(-10)M for the strongly binding TBP protein and 2.3 x 10(-8)M and 2.6 x 10(-8)M for the weaker binding TFIIB and E1A 13S proteins respectively. Non-linear analysis of the appropriate part of the sensorgrams revealed monophasic association and dissociation kinetics for binding between the p65 TAD and all three interaction partners. The remarkable differences in protein affinities add another aspect to a more detailed understanding of formation of the transcription preinitiation complex. The co-transfection of TBP and E1A 13S stimulated NF-kappaB p65-dependent gene expression, showing the biological significance of these interactions. PMID: 9023117 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 7: Mol Cell Biol. 1993 Nov;13(11):6733-41. Functional interaction of the v-Rel and c-Rel oncoproteins with the TATA-binding protein and association with transcription factor IIB. Xu X, Prorock C, Ishikawa H, Maldonado E, Ito Y, Gelinas C. Center for Advanced Biotechnology and Medicine, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5638. Rel family proteins regulate the expression of genes linked to kappa B-binding motifs. Little is known, however, of the mechanism by which they enhance transcription. We have investigated the ability of the v-Rel and c-Rel oncoproteins to interact with components of the basal transcription machinery. Here we report that both the acidic transcription activation domain mapping to the unique C terminus of chicken c-Rel and the F9 cell-specific activation region common to both v-Rel and c-Rel interact with the TATA-binding protein (TBP) and transcription factor IIB (TFIIB) in vitro and in vivo. We also demonstrate that TPB interaction with Rel activation regions leads to synergistic activation of transcription of a kappa B-linked reporter gene. Combined with the observation that the mouse c-Rel and human RelA proteins also interact with TBP and TFIIB in vitro, these results suggest that association with basal transcription factors is important for the transcriptional activities of Rel family proteins. PMID: 8413269 [PubMed - indexed for MEDLINE] ---------------------------------------------------------------