Transcriptional activity of the zinc finger protein NGFI-A is influenced by its interaction with a cellular factor

NGFI-A is an immediate-early gene that encodes a transcription factor whose DNA-binding domain is composed of three zinc fingers. To define the domains responsible for its transcriptional activity, a mutational analysis was conducted with an NGFI-A molecule in which the zinc fingers were replaced by the GAL4 DNA-binding domain. In a cotransfection assay, four activation domains were found within NGFI-A. Three of the activation domains are similar to those characterized previously: one contains a large number of acidic residues, another is enriched in proline and glutamine residues, and another has some sequence homology to a domain found in Krox-20. The fourth bears no resemblance to previously described activation domains. NGFI-A also contains an inhibitory domain whose removal resulted in a 15-fold increase in NGFI-A activity. This increase in activity occurred in all mammalian cell types tested but not in Drosophila S2 cells. Competition experiments in which increasing amounts of the inhibitory domain were cotransfected along with NGFI-A demonstrated a dose-dependent increase in NGFI-A activity. A point mutation within the inhibitory domain of the competitor (I293F) abolished this property. When the analogous mutation was introduced into native NGFI-A, a 17-fold increase in activity was observed. The inhibitory effect therefore appears to be the result of an interaction between this domain and a titratable cellular factor which is weakened by this mutation. Downmodulation of transcription factor activity through interaction with a cellular factor has been observed in several other systems, including the regulation of transcription factor E2F by retinoblastoma protein, and in studies of c-Jun.

Download Full-text

The DNA-binding Domain of Yeast Heat Shock Transcription Factor Independently Regulates Both the N- and C-terminal Activation Domains

Journal of Biological Chemistry ◽

10.1074/jbc.m106301200 ◽

2001 ◽

Vol 276 (43) ◽

pp. 40254-40262 ◽

Cited By ~ 24

Author(s):

Amanda L. Bulman ◽

Susan T. Hubl ◽

Hillary C. M. Nelson

Keyword(s):

Transcription Factor ◽

Heat Shock ◽

Dna Binding ◽

Binding Domain ◽

Heat Shock Transcription Factor ◽

Dna Binding Domain ◽

Activation Domains

Download Full-text

Repression and Activation Domains of Rme1p Structurally Overlap, but Differ in Genetic Requirements

Molecular Biology of the Cell ◽

10.1091/mbc.01-09-0468 ◽

2002 ◽

Vol 13 (5) ◽

pp. 1709-1721 ◽

Cited By ~ 7

Author(s):

Anna Blumental-Perry ◽

Weishi Li ◽

Giora Simchen ◽

Aaron P. Mitchell

Keyword(s):

Dna Binding ◽

Transcriptional Repression ◽

Structural Integrity ◽

Zinc Finger Protein ◽

Zinc Fingers ◽

Binding Domain ◽

Functional Difference ◽

Dna Binding Domain ◽

Yeast Saccharomyces Cerevisiae ◽

Activation Domains

Rme1p, a repressor of meiosis in the yeast Saccharomyces cerevisiae, acts as both a transcriptional repressor and activator. Rme1p is a zinc-finger protein with no other homology to any protein of known function. The C-terminal DNA binding domain of Rme1p is essential for function. We find that mutations and progressive deletions in all three zinc fingers can be rescued by fusion ofRME1 to the DNA binding domain of another protein. Thus, structural integrity of the zinc fingers is not required for the Rme1p-mediated effects on transcription. Using a series of mutant Rme1 proteins, we have characterized domains responsible for repression and activation. We find that the minimal transcriptional repression and activation domains completely overlap and lie in an 88-amino-acid N-terminal segment (aa 61–148). An additional transcriptional effector determinant lies in the first 31 amino acids of the protein. Notwithstanding the complete overlap between repression and activation domains of Rme1p, we demonstrated a functional difference between repression and activation: Rgr1p and Sin4p are absolutely required for repression but dispensable for activation.

Download Full-text

Transcriptional Activity of Sp1 Is Regulated by Molecular Interactions between the Zinc Finger DNA Binding Domain and the Inhibitory Domain with Corepressors, and This Interaction Is Modulated by MEK

Journal of Biological Chemistry ◽

10.1074/jbc.m414134200 ◽

2005 ◽

Vol 280 (30) ◽

pp. 28061-28071 ◽

Cited By ~ 44

Author(s):

Jung-Ahn Lee ◽

Dong-Chul Suh ◽

Jae-Eun Kang ◽

Myung-Hwa Kim ◽

Hyejin Park ◽

...

Keyword(s):

Dna Binding ◽

Zinc Finger ◽

Molecular Interactions ◽

Transcriptional Activity ◽

Binding Domain ◽

Dna Binding Domain ◽

Inhibitory Domain

Download Full-text

Two of the Five Zinc Fingers in the Zap1 Transcription Factor DNA Binding Domain Dominate Site-Specific DNA Binding†

Biochemistry ◽

10.1021/bi0263199 ◽

2003 ◽

Vol 42 (4) ◽

pp. 1053-1061 ◽

Cited By ~ 23

Author(s):

M. V. Evans-Galea ◽

E. Blankman ◽

D. G. Myszka ◽

A. J. Bird ◽

D. J. Eide ◽

...

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Zinc Fingers ◽

Binding Domain ◽

Dna Binding Domain ◽

Site Specific

Download Full-text

Metal-Responsive Transcription Factor 1 (MTF-1) Activity Is Regulated by a Nonconventional Nuclear Localization Signal and a Metal-Responsive Transactivation Domain

Molecular and Cellular Biology ◽

10.1128/mcb.00847-09 ◽

2009 ◽

Vol 29 (23) ◽

pp. 6283-6293 ◽

Cited By ~ 27

Author(s):

Uschi Lindert ◽

Mirjam Cramer ◽

Michael Meuli ◽

Oleg Georgiev ◽

Walter Schaffner

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Nuclear Localization ◽

Nuclear Localization Signal ◽

Zinc Fingers ◽

Binding Domain ◽

Dna Binding Domain ◽

Activation Domain ◽

Localization Signal ◽

Transcription Factor 1

ABSTRACT Metal-responsive transcription factor 1 (MTF-1) mediates both basal and heavy metal-induced transcription of metallothionein genes and also regulates other genes involved in the cell stress response and in metal homeostasis. In resting cells, MTF-1 localizes to both the cytoplasm and the nucleus but quantitatively accumulates in the nucleus upon metal load and under other stress conditions. Here we show that within the DNA-binding domain, a region spanning zinc fingers 1 to 3 (amino acids [aa] 137 to 228 in human MTF-1) harbors a nonconventional nuclear localization signal. This protein segment confers constitutive nuclear localization to a cytoplasmic marker protein. The deletion of the three zinc fingers impairs nuclear localization. The export of MTF-1 to the cytoplasm is controlled by a classical nuclear export signal (NES) embedded in the acidic activation domain. We show that this activation domain confers metal inducibility in distinct cell types when fused to a heterologous DNA-binding domain. Furthermore, the cause of a previously described stronger inducibility of human versus mouse MTF-1 could be narrowed down to a 3-aa difference in the NES; “humanizing” mouse MTF-1 at these three positions enhanced its metal inducibility to the level of human MTF-1.

Download Full-text

Association of p107 with Sp1: genetically separable regions of p107 are involved in regulation of E2F- and Sp1-dependent transcription.

Molecular and Cellular Biology ◽

10.1128/mcb.15.10.5444 ◽

1995 ◽

Vol 15 (10) ◽

pp. 5444-5452 ◽

Cited By ~ 70

Author(s):

P K Datta ◽

P Raychaudhuri ◽

S Bagchi

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Cell Lines ◽

Chimeric Protein ◽

Transient Transfection ◽

Binding Domain ◽

Dna Binding Domain ◽

Related Protein ◽

Activation Domains ◽

Transcription Factor E2f

The retinoblastoma-related protein p107 has been shown to be a regulator of the transcription factor E2F. p107 associates with E2F via its pocket region and represses E2F-dependent transcription. In this study, we provide evidence for a novel interaction between p107 and the transcription factor Sp1. We show that p107 can be found endogenously associated with Sp1 in the extracts of several different cell lines. Moreover, in transient transfection assays, expression of p107 represses Sp1-dependent transcription. This repression of Sp1-dependent transcription does not require the DNA-binding domain of Sp1. Transcription driven by a chimeric protein containing the Ga14 DNA-binding domain and the Sp1 activation domains is inhibited by p107. Interestingly, unlike the repression of E2F-dependent transcription, the repression of Sp1-dependent transcription does not depend on an intact pocket region. We show that distinct regions of p107 are involved in the control of Sp1 and E2F.

Download Full-text

The G115S mutation associated with maturity-onset diabetes of the young impairs hepatocyte nuclear factor 4α activities and introduces a PKA phosphorylation site in its DNA-binding domain

Biochemical Journal ◽

10.1042/bj20040473 ◽

2004 ◽

Vol 383 (3) ◽

pp. 573-580 ◽

Cited By ~ 9

Author(s):

Bénédicte OXOMBRE ◽

Mostafa KOUACH ◽

Ericka MOERMAN ◽

Pierre FORMSTECHER ◽

Bernard LAINE

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Transcriptional Activity ◽

Phosphorylation Site ◽

Binding Domain ◽

Nuclear Factor ◽

Dna Binding Domain ◽

Maturity Onset Diabetes ◽

Hepatocyte Nuclear Factor ◽

Hepatocyte Nuclear Factor 4Α

HNF4α (hepatocyte nuclear factor 4α) belongs to a complex transcription factor network that is crucial for the function of hepatocytes and pancreatic β-cells. In these cells, it activates the expression of a very large number of genes, including genes involved in the transport and metabolism of glucose and lipids. Mutations in the HNF4α gene correlate with MODY1 (maturity-onset diabetes of the young 1), a form of type II diabetes characterized by an impaired glucose-induced insulin secretion. The MODY1 G115S (Gly115→Ser) HNF4α mutation is located in the DNA-binding domain of this nuclear receptor. We show here that the G115S mutation failed to affect HNF4α-mediated transcription on apolipoprotein promoters in HepG2 cells. Conversely, in pancreatic β-cell lines, this mutation resulted in strong impairments of HNF4α transcriptional activity on the promoters of LPK (liver pyruvate kinase) and HNF1α, with this transcription factor playing a key role in endocrine pancreas. We show as well that the G115S mutation creates a PKA (protein kinase A) phosphorylation site, and that PKA-mediated phosphorylation results in a decreased transcriptional activity of the mutant. Moreover, the G115E (Gly115→Glu) mutation mimicking phosphorylation reduced HNF4α DNA-binding and transcriptional activities. Our results may account for the 100% penetrance of diabetes in human carriers of this mutation. In addition, they suggest that introduction of a phosphorylation site in the DNA-binding domain may represent a new mechanism by which a MODY1 mutation leads to loss of HNF4α function.

Download Full-text