| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Division of Reproductive Biology (M.C.), Department of
Gynecology and Obstetrics, Stanford University Medical Center,
Stanford, California 94305,
Institute of Histology and General
Embriology (E.V.), School of Medicine, University La Sapienza,
00161 Rome, Italy
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Although several isoenzymes from different PDE families may be involved in the homeostatic regulation of cAMP levels, it has long been recognized that the cAMP-specific rolipram-sensitive (family 4) PDEs are an essential component of this feedback. In a large variety of cells, an increase in intracellular cAMP is followed by an increase in the activity of one or more cAMP-PDE forms (1). These isoenzymes are encoded by four distinct genes. FSH stimulation of the Sertoli cell causes an increase in PDE activity that is associated with a large increase in PDE4D and PDE4B mRNAs (2, 3). Although message stabilization may play a role, run-on studies have indicated that an increased transcription is the primary cause for the increase in the PDE4D mRNA levels (3). Translation of the accumulated message causes the appearance of a 67 kDa PDE protein in extracts of the Sertoli cell (4). The activity of this PDE protein is responsible for the transient accumulation of cAMP and for induction of a desensitized state (5, 6). Similar regulation of this PDE4D or of the other PDE4 PDEs has been observed in several other hormone-responsive cells (2, 7, 8) as well as inflammatory cells (9, 10, 11). In the latter, this induction is thought to play a crucial role in the control of the inflammatory process (12, 13). In addition to this long-term induction of PDE isoforms, posttranslational modifications may be involved in short-term changes in PDE4 activity (1).
The characterization of the mRNAs derived from the PDE4D gene has led to the discovery that considerable heterogeneity is present at the 5' end of the different transcripts. On the basis of cDNA sequencing (2, 14), RNAse protection (15), or PCR analysis (16, 17), it has been hypothesized that either alternate splicing or the presence of different promoters controlling different transcriptional units are at the origin of this heterogeneity. The PDE4D mRNAs that accumulate in the immature Sertoli cell under basal or after FSH stimulation were analyzed by PCR. Results indicate that two of the four PDE4D mRNA species thus far described are expressed in these cells (16). These have been termed PDE4D1 and PDE4D2. The PDE4D1 and PDE4D2 messages differ only in the presence or absence of a short intron and therefore must originate from the same start site and same promoter (16). The other two known mRNAs derived from the PDE4D gene (PDE4D3 and PDE4D4) are present at very low levels or could not be detected in these immature Sertoli cells (17). In the thyroid cell line FRTL-5, PCR analysis indicated that TSH stimulates the accumulation of PDE4D1 and PDE4D2 but has minor effects on the levels of the PDE4D3 mRNA expressed under basal conditions (17). These findings have prompted the hypothesis that FSH or TSH is regulating the activity of only one of the several promoters that control different transcriptional units in the PDE4D gene. In the present study we have identified this promoter and studied its properties including hormone and cAMP inducibility.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
). PolyA+-RNAs isolated from treated and
untreated immature Sertoli cells in primary cultures were hybridized
with 5'-terminus probes that are specific for the different variants
and with a probe that recognized all the variants in their 3'-end
common region (Fig. 1). Adult testis (Fig. 1) mRNA or FRTL-S cell mRNA
(data not shown) was used as positive control for the expression of
PDE4D3 and PDE4D4 variants. FSH treatment caused a more than 100-fold
increase in PDE4D mRNA as shown by the protected fragments using the
common probe (Fig. 1). However, only PDE4D1 and PDE4D2 variants were
clearly induced by FSH (Fig. 1). Even after overexposure of the gel, a
protected fragment corresponding to PDE4D3 and PDE4D4 could not be
detected by this assay. This finding is consistent with the observation
that hormonal treatment causes the appearance of a 67-kDa PDE protein
in extracts of the Sertoli cell. When expressed in a heterologous
system, the PDE4D2 mRNA is translated into a polypeptide with
immunochemical and biochemical properties identical to the native
FSH-induced 67-kDa protein (17). The other putative promoters present
in the PDE4D gene are not active under basal conditions and are not
activated by FSH stimulation. Ribonuclease protection assay (RPA)
analysis of the FRTL-5 cell mRNA after TSH stimulation confirmed the
induction of PDE4D1 and PDE4D2 in these cells (data not shown).
|
). Several
positive clones were characterized by restriction digestion and by
subcloning and sequencing. A rat genomic EcoRI fragment
containing the two first exons of the message was sequenced in its
entirety. The sequence containing 1540 bp upstream from the putative
initiation of translation is reported in Fig. 2B. A search for TATA box
consensus in the 5'-untranslated region (UT) yielded negative results.
In contrast, three regions of high CG content (CG>95%) were
identified at -390, -450, and -690 upstream from the putative
initiation of translation. These regions resembled GC islands often
observed in promoters that lack a TATA box (19). In these promoters, an
element identified as Inr plays a crucial function in positioning
several components of the RNA polymerase II (20). A potential element
similar to the TdT-Inr (20, 21) was identified surrounding base -341
(TCACTCG).
|
). Sequences similar to inducible activator protein 2 (AP2) and
activator protein 1 (AP1) sites were also identified (Fig. 2B). A cAMP
response element (CRE) consensus site (22) was observed around position
-83. Potentially interesting is the presence of sequences homologous
to NF-KB sites present in the promoter at position -180. It has been
reported that FSH regulates the expression of this transcription factor
(23). Furthermore, TNF treatment causes an increase in PDE4D mRNA in
thyroid cells (24). Comparison of the sequence upstream from the putative initiation of translation was highly conserved between mouse and rat genomic clones (data not shown). One conspicuous difference between the mouse and rat sequence is the insertion of a CA repeat in the mouse (data not shown). Several attempts to determine whether this insert was present in some of the rat alleles not represented in the library failed, suggesting that this repeat may be present exclusively in the mouse gene.
Identification of the Transcription Start Sites
Previous attempts to identify the transcription start sites using
primer extension suggested the presence of several start sites (16).
This is a common finding in promoters that lack a TATA box and contain
GC-rich islands (19). The presence of the GC-rich region rendered
difficult the identification of the number and the exact location of
the initiation of transcription. In an attempt to circumvent this
problem, RNAse protection was used to map the transcription start
site/s using mRNA derived from FSH-stimulated Sertoli cells (Fig. 3). All the probes used generated either one or two
protected fragments. The 5'-boundary of the shorter fragment
corresponds to nucleotide -340 ± 10 from the initiation of
translation. The sequence TGATTCAT in this region conforms with the
signature for a cap site and to an "Inr" sequence (19, 20).
However, the consistent finding of an additional protected fragment
indicates the presence of one or more additional cap sites upstream
from the one identified at -340. This is in agreement with previously
published primer extension data in which two or more extended products
were observed (16). The exact location of the upstream cap site could
not be identified because probes corresponding to region -304 to -700
did not produce a consistent pattern of protection. This may be
attributable to the high GC content of the region.
|
Functional Characterization of the PDE4D1 Promoter
To determine whether the genomic region identified by RNAse
protection can indeed function as a promoter, the EcoRI
fragment identified in Fig. 2B was subcloned upstream of the coding
region of the luciferase cDNA. The promoter activity was studied by
transfection and by measuring the luciferase activity in primary
Sertoli cell cultures in view of the observed large stimulation of
transcription for this gene. Owing to the fact that the transfection
efficiency of the primary Sertoli cell culture is low, the MA-10 Leydig
tumor cell line was also used to confirm the activity obtained in a
more efficient transfection system. A 1.6-kb fragment upstream from the
putative translation start site of PDE4D1 induced luciferase expression
in both transfection systems. A 30-fold increase in luciferase
production was obtained there as compared with a promoterless construct
(Table 1). The activity was approximately one third of
the activity of a promoter of a different PDE4 gene, PDE4B2, which is
also expressed in the Sertoli cell (Table 1). This latter promoter
contains a TATA box and, therefore, is expected to direct transcription
more efficiently. The activity of the PDE4D1 promoter was about one
sixth of that obtained when a strong SV40 promoter was used (Table 1).
Similar results were obtained in MA-10 cells even if the transfection
efficiency was higher in this latter system (data not shown). Treatment
of the transfected cells with (Bu)2cAMP enhanced the
promoter activity. This stimulation is time-dependent, and it is
maximal after 12 h of treatment (data not shown). After this
stimulation, the promoter activity in the presence of
(Bu)2cAMP was approximately one third of that of the strong
SV40 promoter. In all the following experiments, stimulation was
determined after 12 h of incubation.
|
). An increase in luciferase expression was observed
when the proximal cap site was present in the construct. Inclusion of
the region where the upstream cap sites are present produced a further
increase in basal transcription activity (Fig. 4). Conversely,
constructs in which the proximal cap site was deleted (1.2 and 0.9
PDE4D1/2) had consistently less activity than constructs including this
region (1.4 and 1.1 PDE4D1/2) (Fig. 4). This observation is consistent
with the RPA data. Inclusion of most of the 5'-UT produces a further
increase in basal transcription activity, a statistically significant
increase that suggests the presence of basal transcription enhancer in
the 5'-UT of exon 1 of this region. Similar results were obtained after
transfection in MA-10 cells (Fig. 4). From these experiments it was
concluded that this region of genomic DNA has basal promoter activity.
The pattern of promoter activity was also consistent with the
hypothesis that multiple cap sites contribute to the overall
transcription.
|
). Constructs containing the 5'-UT and the
proximal cap site up to base -381 were not inducible by
(Bu)2cAMP. Conversely, the transcription activity of all
the constructs that included a region from -380 to -1218 was
stimulated by (Bu)2cAMP. Maximal stimulation varied between
3- and 6-fold over basal activity (Fig. 5). Inclusion of the 5'-UT
region that contains a putative CRE consensus site produced on average
the highest stimulation; however, this was not statistically different
from the stimulation observed with a construct lacking this region.
Similar results were obtained when FSH was used to measure cAMP levels
in the cell (data not shown).
|
). FSH stimulated the transcription approximately
4-fold with an EC50 of 1 ng/ml. This concentration was in
the same range observed for the induction of the message (3).
|
). The activity of the 1.5-kb
promoter was stimulated by forskolin, cholera toxin, and 8-bromo-cAMP,
but not by 8-bromo-cGMP. On the contrary,
12-O-tetradodecanoyl-phorbol-13-acetate (TPA), an activator
of protein kinase C, marginally stimulated the activity of this
promoter but potentiated the effect of forskolin and
(Bu)2cAMP.
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
In spite of the several different approaches used, for technical reasons it was impossible to conclusively identify the cap sites used in the PDE4D1/D2 promoter. However, the data thus far collected indicate that multiple cap sites may be used. This is consistent with the absence of a TATA box and the presence of GC-rich islands in this region of the sequence. One cap site was identified at -340 from the putative initiation of translation, while one or more may be present upstream of base -593. That sequences up to -340 bp are included in some mRNAs is also supported by the PCR analysis. An alternative explanation of the RPA analysis would be that the -340 bp is an exon/intron boundary and that an additional noncoding exon may be splicing at this point. The possibility that this region corresponds to an intron/exon boundary cannot be formally excluded. However, the boundary mapped by RPA does not contain any splicing signature but has sequence corresponding to a cap site. In addition, the sequence upstream of -340 is highly conserved between rat and mouse. This is a further indication that this is not an intronic sequence but a functionally relevant sequence. Furthermore, some of the mRNAs expressed in the Sertoli cell contain some sequence upstream from this site. Cumulatively, these findings are more in line with the presence of multiple cap sites, the predominant one located at -340. Finally, the region upstream from -340 has clear basal promoter activity when assayed with the luciferase reporter (30-fold increase in luciferase production over a promoterless construct).
The demonstration that an inducible promoter activity can be detected with the region upstream from the sequence of PDE4D1 conclusively defines one of the possible transcriptional units present in this gene. The fact that additional 5'-sequences are present in other mRNAs implies that exons upstream of the promoter identified here are present in the gene. Preliminary characterization of additional genomic clones that we have isolated confirm this hypothesis (S. L. Jin and M. Conti, manuscript in preparation). According to these findings, the promoter directing the PDE4D1/PDE4D2 mRNA transcription is located in an intron. This genomic organization is reminiscent of the structure of the Drosophila dunce gene (26), which is the ancestor of the PD4 genes. Deletion mutations of the 5'-region of the dunce gene have shown that different promoters contribute to the expression in the central nervous system and the reproductive tract of the fly (27). It should be noted that the intronic promoter identified here has not been described in the fly.
Previous runoff experiments indicated that FSH stimulates the transcription of the PDE4D gene approximately 10-fold (3). The transfection experiments with the luciferase reported here show a clear stimulation of transcription of these constructs by both FSH and cAMP analogs (5- to 6-fold stimulation). This stimulation is not as dramatic as what is observed with the accumulation of the PDE4D mRNA. These differences may depend on the fact that 1) elements inhibitory of basal transcription are present in this promoter upstream of -1500 and; 2) that message stabilization plays an important role in the control of the steady state levels of PDE4D1 mRNA. Regardless of the quantitative aspects of the stimulation, these data demonstrate that FSH stimulates the transcription of this gene from this promoter with a consequent increase in PDE4D1/PDE4D2 mRNA. We have shown that only the PDE4D2 protein accumulates in Sertoli cells after FSH stimulation. At present it is not clear why PDE4D1 mRNA is not translated. It is possible that the intron retained in PDE4D1 inhibits the translocation of the message from the nucleus to the cytoplasm, thus preventing or delaying translation. According to this view, only messages with the intron removed are translated into a protein. That unspliced intron sequences serve to control the rate of translation has been shown for several mRNAs (28, 29).
At present it is not clear which promoter elements in this promoter are
responsible for the FSH stimulation of transcription. The promoters of
several genes induced by FSH have been previously characterized. Among
these are the promoter for aromatase (30, 31), RII (32), inhibin-
(33, 34), prodynorphin (35), and urokinase (36). Only in the
inhibin- and the aromatase promoters have CRE elements been clearly
implicated in the FSH activation. The promoter that we have described
here contains the sequence CGACTCA complementary to TGAGTCG where only
the last base is different from a consensus CRE. This sequence is,
however, located in the 5'-UT region that we have shown by PCR and RPA
to be included in the mRNA. Deletion experiments indicate that this
element is not necessary for the FSH induction, but that constructs
containing this 5'-UT region produce the highest stimulation. The exact
role of this 5'-UT region needs to be further investigated. It is
likely that several different enhancer elements contribute to this
activation of transcription by FSH. Several putative AP-2 consensus
sites (37) are present at -378, -770, -788, and -1208, and these
may be involved in the FSH activation. The synergistic effect of TPA
and (Bu)2cAMP on this promoter is consistent with this AP-2
involvement in the activation. Interestingly, the region
-530CGGGAGGGGCGGT-518 upstream from the first
cap site has considerable homologies with an element involved in cAMP
stimulation in the human urokinase gene (36). This promoter is
activated by FSH when transfected in mouse Sertoli cells. This region
is also similar to other GC-rich elements that are cAMP-inducible (38, 39). Further experiments are necessary to determine the role of this
region of the PDE4D1 promoter in hormone activation.
In summary, our findings demonstrate the presence of an intronic promoter in the PDE4D gene that directs the expression of a truncated PDE form (17). This truncated PDE is a component of a feedback loop present in the cell and is involved in the termination of the hormone stimulus or desensitization (18). The organization of this gene is strikingly similar to that of other genes involved in the cAMP-dependent pathway. For instance, the CRE modulator (CREM), a transcription factor that mediates the cAMP regulation of gene expression, contains several promoters. A cAMP-regulated intronic promoter in this CREM gene directs the expression of a truncated protein, inducible cAMP early repressor (ICER), that functions as transcriptional suppressor (40). Therefore, both in the PDE4D and in the CREM gene, a cAMP-regulated intronic promoter is involved in the termination/modulation of the cAMP signal. It remains to be determined whether the PDE promoter characterized is the only inducible promoter present in this gene and whether additional signal transduction pathways regulate these promoters.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
-32P]UTP (3000Ci/mmol) was manufactured by NEN
Research Products (Boston, MA). All other chemicals used were
analytical grade and purchased from Sigma (St. Louis, MO) or Bio-Rad
(Richmond, CA).
Plasmid Constructions
pGL2-Basic, a promoterless luciferase vector (Promega) was used
to test the various sequences of the ratPDE3/IVD gene for promoter
activity. The different length fragments of the putative gene promoter
were isolated from a genomic clone (
DASH II-ratPDE 3.2) containing
the 5'-flanking region previously characterized (16). To subclone the
genomic fragments into the pGL2-Basic vector, two different strategies
were used. In some cases the fragment was first subcloned into pB KS II
vector (Stratagene, La Jolla, CA), and excised using restriction sites
compatible with pGl2-Basic polylinker, and the insert was transferred
to this latter vector. This strategy was used to obtain 1.2PDE3-luc
(-1540/-354) and 0.9PDE3-luc (-1218/-354) constructs, where the
coordinates are specified relative to the first AUG (+1). In other
cases, the DNA fragments were obtained by PCR using the DASH
II-ratPDE 3.2 genomic clone as a template and synthetic
oligonucleotides containing the appropriate restriction sites.
1.5PDE3-luc (-1540/+ 2), 1.4PDE3-luc (-1540/-121), 1.1PDE3-luc
(-1218/-121), 0.3PDE3-luc (-381/-121), and 0.2PDE3-luc
(-299/-121) constructs were achieved with this cloning strategy.
To perform the RPA, four different genomic fragments were subcloned in pB KS II vector. The sequences were amplified by PCR from the l DASH II-ratPDE 3.2 genomic clone and subcloned in the SmaI site of the vector. The sequences of the primers used and the corresponding constructs are listed below: oligonucleotide A (5'-GAGCCGGGGTCTGCGGGACG-3') and oligonucleotide B (5'-CGCACATGAGGGCTGCTCCTTCATATTGCAGAGC-3') for pBS KS II-A (-299/+24) construct; oligonucleotide C (5'-GACTTGAGCGACAAAACAGGAAA-3') and oligonucleotide A for the pBS KS II-B (-381/+24) construct; oligonucleotide D (5'-TCCCGGCTGCGCTTCAAAGCAGTGG-3') and oligonucleotide E (5'-TTTCCTGTTTTGTCGCTCAAGTC-3') for pBS KS II-C (-593/-359) construct; oligonucleotide F (5'-GACTTGAGCGACAAAACAGGAAA-3') and oligonucleotide G (5'-GCAAGGCCAACTTTGGCACG-3') for pBS KS II-D (-381/-121) construct.
Ribonuclase Protection Assay
Run-off transcripts were synthesized from each linearized
template using a Transcription in vitro System Kit (Promega)
and either T3 or T7 polymerase. The full-length single-stranded RNA
probes were purified by acrylamide gel electrophoresis. Poly (A+) RNA
was purified from Sertoli cell culture treated for 24 h with 1
mM (Bu)2cAMP, using a Quick Prep mRNA
Purification Kit (Pharmacia) according to the supplied protocol. The
RPA (41) was performed with RPA II Kit (Ambion, Austin, TX) using 5
µg extracted mRNA and 1.5–2 105 cpm of labeled probe for
each reaction. Nuclease-resistant probes were visualized by gel
electrophoresis \[5% acrylamide, 8 M urea and 90
mM Tris Borate, 2 mM EDTA (TBE)\] and
autoradiography.
Sertoli Cell Culture and Transfection
Sertoli cell cultures were prepared from 15 day-old
Sprague-Dawley rats following a procedure previously reported (42), and
cells were seeded on 90-mm plastic tissue culture dishes in a
serum-free Eagle’s MEM supplemented with glutamine, nonessential amino
acids, pyruvic acid, gentamycin, streptomycin, and penicillin.
Incubation was carried out at 32 C in a controlled atmosphere of 95%
air-5% CO2, and cultures were used for transfection
experiments 3 days later. Cells were cotransfected with the
CaPO4-DNA coprecipitate technique using 15 µg reporter
construct per plate (1.5 µg/ml) and 3 µg pCMV-ßgal (0.3 µg/ml)
to allow normalization to ß-galactosidase expression. After 4 h
the medium was aspirated and the cultures were subjected for 2 min to
10% glycerol hyperosmotic shock and fed with fresh medium containing
or lacking 1 mM (Bu)2cAMP. After 12 h,
cells were harvested and lysates assayed for luciferase and
ß-galactosidase activity as described below.
Assay of Luciferase and ß-Galactosidase Activity
Individual dishes were washed twice with PBS then scraped in 1x
Reporter Lysis Buffer (Promega). The cell lysates were centrifuged
(16,000 x g, 2 min) at 4 C, and the supernatants were
assayed. Luciferase activity (43) was performed in duplicate, mixing 20
µl cell extract with 100 µl Luciferase Assay Reagent (Promega). The
produced light was measured in an Auto Climat Lumat LB 952 T/16
luminometer (Berthold, Nashua, NH) and expressed as relative light
units (RLU). ß-Galactosidase assay was performed in duplicate, by
adding to the cell extracts an equal volume of Assay 2x Buffer
(Promega). The samples were incubated at 37 C until a yellow color
developed. In each assay a standard curve with different amounts of
purified-galactosidase enzyme (Promega) was performed. After the
incubation the absorbance of the samples was read at 420 nm in a
spectrophotometer (Beckman, Fullerton, CA). ß-Galactosidase
milliunits in each sample were calculated using the standard curve.
Luciferase activity (RLU) was normalized relative to ß-galactosidase
activity (milliunits) to correct for differences in transfection
efficiency.
|
ACKNOWLEDGMENTS |
|---|
These studies were supported by NIH Grant HD-20788 from the National Institute of Child Health and Human Development. E.V. was supported in part by grants from the Italian National Research Council (CNR) targeted projects "Clinical Applications and Oncological Research" (ACRO Contract 051601087) and from the "Istituto Superiore della Sanita" (9306–28).
|
FOOTNOTES |
|---|
Received for publication July 15, 1996. Accepted for publication March 13, 1997.
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
This article has been cited by other articles:
 |
|
 |
|
  M. P. Kelly, Y.-F. Cheung, C. Favilla, S. J. Siegel, S. J. Kanes, M. D. Houslay, and T. Abel Constitutive activation of the G-protein subunit G{alpha}s within forebrain neurons causes PKA-dependent alterations in fear conditioning and cortical Arc mRNA expression Learn. Mem., January 28, 2008; 15(2): 75 - 83. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. C. Kostek, Y.-W. Chen, D. J. Cuthbertson, R. Shi, M. J. Fedele, K. A. Esser, and M. J. Rennie Gene expression responses over 24 h to lengthening and shortening contractions in human muscle: major changes in CSRP3, MUSTN1, SIX1, and FBXO32 Physiol Genomics, September 11, 2007; 31(1): 42 - 52. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Levallet, J. Levallet, H. Bouraima-Lelong, and P.-J. Bonnamy Expression of the cAMP-Phosphodiesterase PDE4D Isoforms and Age-Related Changes in Follicle-Stimulating Hormone-Stimulated PDE4 Activities in Immature Rat Sertoli Cells Biol Reprod, May 1, 2007; 76(5): 794 - 803. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Houslay, G. S. Baillie, and D. H. Maurice cAMP-Specific Phosphodiesterase-4 Enzymes in the Cardiovascular System: A Molecular Toolbox for Generating Compartmentalized cAMP Signaling Circ. Res., April 13, 2007; 100(7): 950 - 966. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Omori and J. Kotera Overview of PDEs and Their Regulation Circ. Res., February 16, 2007; 100(3): 309 - 327. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. G. Tilley and D. H. Maurice Vascular Smooth Muscle Cell Phenotype-Dependent Phosphodiesterase 4D Short Form Expression: Role of Differential Histone Acetylation on cAMP-Regulated Function Mol. Pharmacol., September 1, 2005; 68(3): 596 - 605. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. Houslay The Long and Short of Vascular Smooth Muscle Phosphodiesterase-4 As a Putative Therapeutic Target Mol. Pharmacol., September 1, 2005; 68(3): 563 - 567. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Wallace, L. A. Johnston, E. Huston, D. MacMaster, T. M. Houslay, Y.-F. Cheung, L. Campbell, J. E. Millen, R. A. Smith, I. Gall, et al. Identification and Characterization of PDE4A11, a Novel, Widely Expressed Long Isoform Encoded by the Human PDE4A cAMP Phosphodiesterase Gene Mol. Pharmacol., June 1, 2005; 67(6): 1920 - 1934. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Euskirchen, T. E. Royce, P. Bertone, R. Martone, J. L. Rinn, F. K. Nelson, F. Sayward, N. M. Luscombe, P. Miller, M. Gerstein, et al. CREB Binds to Multiple Loci on Human Chromosome 22 Mol. Cell. Biol., May 1, 2004; 24(9): 3804 - 3814. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-Y. Park, F. Richard, S.-Y. Chun, J.-H. Park, E. Law, K. Horner, S-L C. Jin, and M. Conti Phosphodiesterase Regulation Is Critical for the Differentiation and Pattern of Gene Expression in Granulosa Cells of the Ovarian Follicle Mol. Endocrinol., June 1, 2003; 17(6): 1117 - 1130. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Conti, W. Richter, C. Mehats, G. Livera, J.-Y. Park, and C. Jin Cyclic AMP-specific PDE4 Phosphodiesterases as Critical Components of Cyclic AMP Signaling J. Biol. Chem., February 14, 2003; 278(8): 5493 - 5496. [Full Text] [PDF]
|
|
|
|
|
|
I. R. Le Jeune, M. Shepherd, G. Van Heeke, M. D. Houslay, and I. P. Hall Cyclic AMP-dependent Transcriptional Up-regulation of Phosphodiesterase 4D5 in Human Airway Smooth Muscle Cells. IDENTIFICATION AND CHARACTERIZATION OF A NOVEL PDE4D5 PROMOTER J. Biol. Chem., September 20, 2002; 277(39): 35980 - 35989. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Mehats, G. Tanguy, E. Dallot, D. Cabrol, F. Ferre, and M.-J. Leroy Is Up-Regulation of Phosphodiesterase 4 Activity by PGE2 Involved in the Desensitization of {beta}-Mimetics in Late Pregnancy Human Myometrium? J. Clin. Endocrinol. Metab., November 1, 2001; 86(11): 5358 - 5365. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Persani, S. Borgato, A. Lania, M. Filopanti, G. Mantovani, M. Conti, and A. Spada Relevant cAMP-Specific Phosphodiesterase Isoforms in Human Pituitary: Effect of Gs{alpha} Mutations J. Clin. Endocrinol. Metab., August 1, 2001; 86(8): 3795 - 3800. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Rena, F. Begg, A. Ross, C. MacKenzie, I. McPhee, L. Campbell, E. Huston, M. Sullivan, and M. D. Houslay Molecular Cloning, Genomic Positioning, Promoter Identification, and Characterization of the Novel Cyclic AMP-Specific Phosphodiesterase PDE4A10 Mol. Pharmacol., April 16, 2001; 59(5): 996 - 1011. [Abstract] [Full Text]
|
|
|
|
|
|
L. Persani, A. Lania, L. Alberti, R. Romoli, G. Mantovani, S. Filetti, A. Spada, and M. Conti Induction of Specific Phosphodiesterase Isoforms by Constitutive Activation of the cAMP Pathway in Autonomous Thyroid Adenomas J. Clin. Endocrinol. Metab., August 1, 2000; 85(8): 2872 - 2878. [Abstract] [Full Text]
|
|
|
|
 |
|
 F. Naro, C. Sette, E. Vicini, V. De Arcangelis, M. Grange, M. Conti, M. Lagarde, M. Molinaro, S. Adamo, and G. Némoz Involvement of Type 4 cAMP-Phosphodiesterase in the Myogenic Differentiation of L6 Cells Mol. Biol. Cell, December 1, 1999; 10(12): 4355 - 4367. [Abstract] [Full Text]
|
|
|
|
 |
|
 C. Méhats, G. Tanguy, E. Dallot, B. Robert, R. Rebourcet, F. Ferré, and M. J. Leroy Selective Up-Regulation of Phosphodiesterase-4 Cyclic Adenosine 3',5'-Monophosphate (cAMP)-Specific Phosphodiesterase Variants by Elevated cAMP Content in Human Myometrial Cells in Culture Endocrinology, July 1, 1999; 140(7): 3228 - 3237. [Abstract] [Full Text]
|
|
|
|
|
|
M. Salanova, S.-Y. Chun, S. Iona, C. Puri, M. Stefanini, and M. Conti Type 4 Cyclic Adenosine Monophosphate-Specific Phosphodiesterases Are Expressed in Discrete Subcellular Compartments during Rat Spermiogenesis Endocrinology, May 1, 1999; 140(5): 2297 - 2306. [Abstract] [Full Text]
|
|
|
|
|
|
L. M. Grønning, M. K. Dahle, K. A. Taskén, S. Enerbäck, L. Hedin, K. Taskén, and H. K. Knutsen Isoform-Specific Regulation of the CCAAT/Enhancer-Binding Protein Family of Transcription Factors by 3',5'-Cyclic Adenosine Monophosphate in Sertoli Cells Endocrinology, February 1, 1999; 140(2): 835 - 843. [Abstract] [Full Text]
|
|
|
|
|
|
S.-L. C. Jin, T. Bushnik, L. Lan, and M. Conti Subcellular Localization of Rolipram-sensitive, cAMP-specific Phosphodiesterases. DIFFERENTIAL TARGETING AND ACTIVATION OF THE SPLICING VARIANTS DERIVED FROM THE PDE4D GENE J. Biol. Chem., July 31, 1998; 273(31): 19672 - 19678. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. J. TORPHY Phosphodiesterase Isozymes . Molecular Targets for Novel Antiasthma Agents Am. J. Respir. Crit. Care Med., February 1, 1997; 157(2): 351 - 370. [Full Text]
|
|
|
|
|
|
K. A. Tasken, P. Collas, W. A. Kemmner, O. Witczak, M. Conti, and K. Tasken Phosphodiesterase 4D and Protein Kinase A Type II Constitute a Signaling Unit in the Centrosomal Area J. Biol. Chem., June 15, 2001; 276(25): 21999 - 22002. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Liu, D. Palmer, S. L. Jimmo, D. G. Tilley, H. A. Dunkerley, S. C. Pang, and D. H. Maurice Expression of Phosphodiesterase 4D (PDE4D) Is Regulated by Both the Cyclic AMP-dependent Protein Kinase and Mitogen-activated Protein Kinase Signaling Pathways. A POTENTIAL MECHANISM ALLOWING FOR THE COORDINATED REGULATION OF PDE4D ACTIVITY AND EXPRESSION IN CELLS J. Biol. Chem., August 18, 2000; 275(34): 26615 - 26624. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
