1: Gene. 2005 Oct 10; [Epub ahead of print] 

Induction of human LTBP-3 promoter activity by TGF-beta1 is mediated by Smad3/4
and AP-1 binding elements.

Kantola AK, Keski-Oja J, Koli K.

Departments of Virology and Pathology, Haartman Institute and Helsinki
University Hospital, University of Helsinki, Biomedicum Rm A506, P.O.Box 63,
Haartmaninkatu 8, 00014 Helsinki, Finland.

Latent TGF-beta binding proteins (LTBPs) are extracellular matrix glycoproteins,
which are essential for the targeting and activation of TGF-betas. LTBP-3
regulates the bioavailability of TGF-beta especially in the bone. To understand
the regulation of LTBP-3 expression, we have isolated and characterized the
promoter region of human LTBP-3 gene. The GC-rich TATA-less promoter contained
several transcription initiation sites and putative binding sites for multiple
sequence specific transcription factors including Sp1, AP-1, c-Ets, MZF-1, Runx1
and members of the GATA-family. Reporter gene analyses of the promoter indicated
that it was more active in MG-63 than in Saos-2 osteosarcoma cells, suggesting
that it is regulated as the endogenous gene. TGF-beta1 stimulated the
transcriptional activity of LTBP-3 promoter in MG-63 cells, while certain other
bone-derived growth factors and hormones were ineffective. TGF-beta1 increased
LTBP-3 mRNA levels accordingly. Analyses of deletion constructs of the promoter
and mutational deletion of specific transcription factor binding sites indicated
that Smad3/4 and AP-1 binding sites mediated the TGF-beta1 response. The
involvement of AP-1 activity was further indicated by decreased TGF-beta
responsiveness of the LTBP-3 promoter in the presence of a MEK/Erk signaling
pathway inhibitor. Our results suggest an important new role for TGF-beta1 in
the regulation of its binding protein, LTBP-3.

PMID: 16223572 [PubMed - as supplied by publisher]


---------------------------------------------------------------


2: J Immunol. 2003 Dec 15;171(12):6611-20. 

Transcriptional regulation of ILT family receptors.

Nakajima H, Asai A, Okada A, Ping L, Hamajima F, Sata T, Isobe K.

Department of Basic Gerontology, National Institute for Longevity Sciences, Obu,
Aichi, Japan. hideonak@nils.go.jp

Ig-like transcripts (ILT/leukocyte Ig-like receptor/monocyte/macrophage Ig-like
receptor or CD85) are encoded on human chromosome 19q13.4, designated the human
leukocyte receptor complex, and are predominantly expressed on myeloid lineage
cells. We investigated the transcriptional regulation of ILT1, ILT2, and ILT4
genes to elucidate control mechanisms operating on the specific expression of
ILT receptors. Inhibitory ILT2 and ILT4 both have a similar genomic structure,
in which the approximately 160-bp 5'-flanking regions function as core promoters
with critically important PU.1 binding sites. However, an Sp1 family-binding
GC-box is more influential in trans-activation of ILT2 than ILT4. Additionally,
ILT4 transcription is tightly regulated by chromatin modifications accompanied
by histone acetylation, which strictly controls expression within myeloid
lineage cells. Activating ILT1 carries a core promoter corresponding to the
intronic region of ILT2 and ILT4, where PU.1 and Runx1 binding sites are
essential, but a downstream heat shock element also augments promoter activity.
Thus, each ILT is regulated by a distinct transcriptional mechanism, although
PU.1 acts as a common trans-acting factor. We also found that human CMV
infection strongly trans-activates inhibitory ILT2 and ILT4 genes through the
expression of immediate-early proteins.

PMID: 14662864 [PubMed - indexed for MEDLINE]


---------------------------------------------------------------


3: J Leukoc Biol. 2003 Feb;73(2):263-72. 

Characterization of promoter elements directing Mona/Gads molecular adapter
expression in T and myelomonocytic cells: involvement of the AML-1 transcription
factor.

Guyot B, Mouchiroud G.

Centre de Genetique Moleculaire et Cellulaire, UMR CNRS 5534, Universite Claude
Bernard Lyon-1, Batiment Gregor Mendel, 16 rue Raphael Dubois, 69622
Villeurbanne Cedex, France.

Monocytic adaptor (Mona, also called Gads) is a molecular adaptor implicated in
T cell activation and macrophage differentiation. The objective of this study
was to identify elements regulating specific expression of Mona/Gads in human T
cell and myelomonocytic cell lines. We first confirmed that the -2000 to +150
genomic region relative to the Mona gene transcription start site is sufficient
to direct specific reporter gene expression in T cell lines, Jurkat, and MOLT-4
and in the immature myeloid cell lines, KG1a and RC2A. Deletion analysis and
electrophoresis mobility shift assay identified several cis regulatory elements:
overlapping initiator sequences, one interferon response factor-2
(IRF-2)-binding site at position -154, one GC box recognized by Sp1 and Sp3 at
position -52, and two acute myeloid leukemia (AML)-1 binding sites at positions
-70 and -13. Site-directed mutagenesis experiments indicated a key role of AML-1
for driving Mona expression in T cells and myeloid cells, and involvement of
Sp1/Sp3 and IRF-2 transcription factors to modulate Mona expression in a
cell-specific manner.

PMID: 12554803 [PubMed - indexed for MEDLINE]


---------------------------------------------------------------


4: J Cell Biochem. 1997 Jul 1;66(1):123-32. 

Subcellular partitioning of transcription factors during osteoblast
differentiation: developmental association of the AML/CBF alpha/PEBP2
alpha-related transcription factor-NMP-2 with the nuclear matrix.

Lindenmuth DM, van Wijnen AJ, Hiebert S, Stein JL, Lian JB, Stein GS.

Department of Cell Biology, University of Massachusetts Medical School and
Cancer Center, Worcester, 01655, USA.

The subnuclear location of transcription factors may functionally contribute to
the regulation of gene expression. Several classes of gene regulators associate
with the nuclear matrix in a cell type, cell growth, or cell cycle
related-manner. To understand control of nuclear matrix-transcription factor
interactions during tissue development, we systematically analyzed the
subnuclear partitioning of a panel of transcription factors (including
NMP-1/YY-1, NMP-2/AML, AP-1, and SP-1) during osteoblast differentiation using
biochemical fractionation and gel shift analyses. We show that nuclear matrix
association of the tissue-specific AML transcription factor NMP-2, but not the
ubiquitous transcription factor YY1, is developmentally upregulated during
osteoblast differentiation. Moreover, we show that there are multiple AML
isoforms in mature osteoblasts, consistent with the multiplicity of AML factors
that are derived from different genes and alternatively spliced cDNAs. These AML
isoforms include proteins derived from the AML-3 gene and partition between
distinct subcellular compartments. We conclude that the selective partitioning
of the YY1 and AML transcription factors with the nuclear matrix involves a
discriminatory mechanism that targets different classes and specific isoforms of
gene regulatory factors to the nuclear matrix at distinct developmental stages.
Our results are consistent with a role for the nuclear matrix in regulating the
expression of bone-tissue specific genes during development of the mature
osteocytic phenotype.

PMID: 9215534 [PubMed - indexed for MEDLINE]


---------------------------------------------------------------


5: Proc Natl Acad Sci U S A. 1996 Mar 5;93(5):1935-40. 

Expression of the human acute myeloid leukemia gene AML1 is regulated by two
promoter regions.

Ghozi MC, Bernstein Y, Negreanu V, Levanon D, Groner Y.

Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot,
Israel.

The human chromosome 21 AML1 gene is expressed predominantly in the
hematopoietic system. In several leukemia-associated translocations AML1 is
fused to other genes and transcription of the fused regions is mediated by
upstream sequences that normally regulate the expression of AML1. The 5' genomic
region of AML1 was cloned and sequenced. The two 5' untranslated regions (UTRs)
previously identified in AML1 cDNAs were located in this region and the distance
between them was established. The distal 5' UTR maps over 7 kb upstream of the
proximal one. Using primer extension with mRNA, transcription start sites were
identified at two distinct sites above these 5' uTRs. Sequence analysis revealed
the absence of a TATA motif and the presence of Sp1, PU.1, Oct, CRE, Myb, Ets,
and Ets-like binding sites in both upstream regions. Several initiator elements
(Inr) that overlap the transcription start sites were also identified. These
proximal and distal upstream regions and their deletion mutants were cloned in
front of a luciferase reporter gene and used in transfection assays. We
demonstrate that both upstream regions function as promoters in hematopoietic
(Jurkat) and nonhematopoietic (HEK) cell lines. The activity of both promoters
was orientation dependent and was enhanced, in a cell-type specific manner, by a
heterologous enhancer sequence. These results indicate that additional control
elements, either negative or positive, regulate the tissue-specific expression
of AML1.

PMID: 8700862 [PubMed - indexed for MEDLINE]


---------------------------------------------------------------