ACCELERATED PUBLICATION
Phosphodiesterase 4D and Protein Kinase A Type II Constitute a
Signaling Unit in the Centrosomal Area*
Kristin A.
Taskén
,
Philippe
Collas
,
Wolfram A.
Kemmner§,
Oliwia
Witczak
,
Marco
Conti¶, and
Kjetil
Taskén
From the
Institute of Medical Biochemistry,
University of Oslo, N-0317 Oslo, Norway, the
§ Max-Planck Institute for Developmental Biology, Department
of Biochemistry, D-72076 Tübingen, Germany, and the
¶ Department of Gynecology & Obstetrics, Stanford University
Medical Center, Stanford, California 94305-5317
Received for publication, December 22, 2000, and in revised form, March 26, 2001
 |
ABSTRACT |
The mediation of cAMP effects by specific pools
of protein kinase A (PKA) targeted to distinct subcellular domains
raises the question of how inactivation of the cAMP signal is achieved locally and whether similar targeting of phosphodiesterases (PDEs) to
sites of cAMP/PKA action could be observed. Here, we demonstrate that
Sertoli cells of the testis contain an insoluble PDE4D3 isoform, which
is shown by immunofluorescence to target to centrosomes. Staining of
PDE4D and PKA shows co-localization of PDE4D with PKA-RII
and RII
in the centrosomal region. Co-precipitation of RII subunits and PDE4D3
from cytoskeletal extracts indicates a physical association of the two
proteins. Distribution of PDE4D overlaps with that of the centrosomal
PKA-anchoring protein, AKAP450, and AKAP450, PDE4D3, and PKA-RII
co-immunoprecipitate. Finally, both PDE4D3 and PKA co-precipitate with
a soluble fragment of AKAP450 encompassing amino acids 1710 to 2872 when co-expressed in 293T cells. Thus, a centrosomal complex
that includes PDE4D and PKA constitutes a novel signaling unit that may
provide accurate spatio-temporal modulation of cAMP signals.
 |
INTRODUCTION |
The broad specificity protein kinase A
(PKA)1 and phosphodiesterases
(PDEs) have complementary roles in cAMP signaling. Whereas PKA
phosphorylation is activated by cAMP (1), PDEs degrade cAMP and
inactivate the cAMP signal (2). Subcellular targeting of components in
the cAMP signaling pathway is essential to elicit discrete cellular
effects. Compartmentalization of PKA is mediated by interaction with a
number of protein kinase A-anchoring proteins (AKAPs) (3), whereas
little is known about subcellular targeting of PDEs even though
examples of interactions with putative anchor proteins is now emerging
as shown e.g. for PDE4D3 (4) and PDE4D5 (5). Here we
have investigated the colocalization of PDE4D and PKA regulatory
subunits in an endocrine cell and provided evidence that PDE4D3 and PKA
are in a functional complex coordinated by AKAP450.
 |
EXPERIMENTAL PROCEDURES |
Cell Culture--
Sertoli cell primary cultures were prepared
from testes of 19-day-old Harlan Sprague Dawley rats (B&K Universal AS,
Nittedal, Norway) according to the method of Dorrington et
al. (34) with some modifications (6). The cells were plated
in 10-cm culture dishes (Nunc, Copenhagen, Denmark) for protein
analysis and cultured in Eagle's minimum essential medium (Life
Technologies, Inc.; Grand Island, NY) with addition of streptomycin
(100 mg/liter), penicillin (105 IU/liter), fungizone (0.25 mg/liter), L-glutamine (2 mM), and fetal calf
serum (10% Life Technologies, Inc.) at 32 °C in a humidified atmosphere with 5% CO2. After 3 days, the cells were
incubated further in serum-free modified minimum essential medium. For
immunocytochemistry, Sertoli cells were plated densely to avoid
overgrowth of peritubular cells, cultured for 4 days to allow release
of germinal cells, and then trypsinized and replated on glass
coverslips at lower density to allow examination of single cells.
Cell Fractionation--
Sertoli cells (10 culture dishes; 10 cm;
~12 × 106 cells/dish) were washed in cold
phosphate-buffered saline and then scraped in isotonic buffer (250 mM sucrose, 20 mM Tris-Cl, pH 7.8, 1 mM EGTA, 10 mM MgCl2, 50 mM NaF, 10 mM
-mercaptoethanol, 50 mM benzamidine, 2 mM PMSF, and
CompleteTM antiprotease mix; Roche Molecular Biochemicals),
homogenized (Dounce homogenizer, 10 strokes), and centrifuged at
200,000 × g. Supernatants (S200) and subsequent
extracts of the pellet in isotonic buffer with 1% Triton X-100
(15,000 × g supernatant, TX-100) and then with RIPA
buffer (15,000 × g supernatant, RIPA, 150 mM NaCl, 50 mM Tris-Cl, pH 8.0, 1% Nonidet
P-40, 0.5% deoxycholate, 0.1% SDS) were prepared.
Immunological Procedures and Antibodies--
Immunoblotting,
immunoprecipitation, and immunofluorescence analyses were performed as
described elsewhere (7, 8). For immunofluorescence, observations were
made with an Olympus BX60 microscope, and photographs were taken with a
JVC camera and AnalySIS software (Soft Imaging Systems). Monoclonal Ab
M3S1 directed against PDE4D (9), mAbs directed against RI
, RII
,
and RII
(cat. nos. P53620, P55120, and 54720, respectively;
developed by K. Taskén in collaboration with Transduction
Laboratories, Lexington, KY) (10, 11), and affinity-purified rabbit
polyclonal antibodies against RII
and RII
(12) were used for
Western blotting, immunoprecipitation, and immunofluorescence as
indicated in the figure legends. The centrosomal marker mAb CTR453 (13) was kindly supplied by Dr. Michel Bornens, Curie Institute, Paris, France. A24 antibody was raised against a purified recombinant fragment
of the chicken AKAP450, affinity purified and characterized and shown
to specifically interact with human
AKAP450.2 The anti-GFP
antibody was from CLONTECH (Palo Alto, CA).
 |
RESULTS AND DISCUSSION |
We investigated localization of PDEs in Sertoli cell primary
cultures that are highly hormonally responsive and known to contain isoforms of the cAMP-specific PDE4D (14). Subcellular fractionation of
Sertoli cells from 19-day-old rats revealed the presence of a soluble
PDE4D1/2 (Fig. 1a,
S200), which was highly inducible by cAMP (compare basal
(B) versus stimulated (S)).
Furthermore, an insoluble PDE4D3 isoform was observed in the pellet
from the 200,000 × g fractionation, a majority of
which could be solubilized by non-ionic detergent (Fig. 1a,
Tx-100). In addition, a minor pool of PDE4D3 that remained
in the pellet after repeated detergent extraction could be extracted by
a RIPA buffer containing 0.1% SDS (Fig. 1, a and
b, RIPA). In agreement with observations made in
thyroid cells, the level of PDE4D3 was not regulated by cAMP (15).
Examination of PKA distribution revealed RII
associated with soluble
and particulate fractions, whereas RII
was present at lower levels
but was induced by cAMP in all cellular compartments (as described
previously in Refs. 16 and 17). Notably, induction of RII
by cAMP
seemed to displace RII
from the particulate fraction. RI
was
mainly present in the soluble fraction but appeared also in particulate
fractions after cAMP treatment.

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Fig. 1.
Subcellular localization of PDE4D isoforms in
Sertoli cells. a, Sertoli cell primary cultures from
19-day-old rats were incubated with a permeable cAMP analog, 8-CPTcAMP
(100 µM), for 24 h (S) or left untreated
(B) and subsequently homogenized in isotonic buffer.
Supernatants (S200) and subsequent extracts of the pellet in
isotonic buffer with 1% Triton X-100 (15,000 × g
supernatant, Tx-100) and then with RIPA buffer (15,000 × g supernatant, RIPA) were subjected to
SDS-PAGE (40 µg of each fraction) and immunoblot analysis for the
presence of PDE4D (upper panel, M3S1 mAb that recognizes all
PDE4D isoforms; similar data were obtained with mAb F34-8F4 from
Pfizer), RII (upper middle panel), RII (lower
middle panel), and RI (lower panel). The mobility of
molecular size markers (in kDa) are indicated. b, cells were
fractionated to yield a RIPA extract from the detergent-insoluble
fraction as in a and subjected to immunoblot analysis for
PDE4D. Recombinant PDE4D2 and PDE4D3 were used as standards
(Std.). A representative of three experiments is
shown.
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|
Investigation of the PDE4D subcellular distribution by immunostaining
demonstrated distinct perinuclear dots (Fig.
2a, upper and
lower panels, green label) that could be
identified as centrosomes by co-labeling with a centrosomal marker
(compare Figs. 2c and 4a). In addition, some
weaker and more disperse staining was observed in the Golgi region that
could account for the detergent-soluble PDE4D3. In co-staining with
RII
, PDE4D and RII
co-localized, but RII
had a wider
distribution in the Golgi-centrosomal area (Fig. 2a,
red label; co-localization appears yellow) as
also described for a number of other cell types (12). In contrast,
RII
was only detected at low levels in the Golgi-centrosomal region
of unstimulated cells and was distinctly co-localized with PDE4D in the
centrosomal region of cAMP-treated cells (Fig. 2a,
lower panels). Cyclic AMP treatment also induced strong
labeling of PDE4D in the cytoplasm (Fig. 2a, right
panels). This staining most likely represents the cAMP-induced
soluble PDE4D1/2 described in Fig. 1, as fixation with cold methanol
extracted the cytoplasmic PDE4D staining (Fig. 2b). Dual
immunofluorescence labeling of cAMP-treated Sertoli cells for RII
and a well-characterized centrosomal marker, CTR453 (13), revealed a
full overlap in the merged image (Fig. 2c). This implies
that RII
and PDE4D (Fig. 2a, lower right panel) are targeted to the centrosomal region. Compared with the immunoreactive PKA and PDE4D in the soluble S200 fraction, there is an
apparent lack of cytoplasmatic PKA and PDE by immunostaining, presumably because such diffuse signals are below the detection level.

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Fig. 2.
Immunolocalization of PDE4D and PKA in
Sertoli cells. Sertoli cells were stimulated with 300 µM 8-CPTcAMP for 48 h (a, right
panels, b and c) or left untreated
(a, left panels). Cells were fixed with 3%
paraformaldehyde and permeabilized with 0.5% Triton X-100
(a, b, left panel, and c)
or simultaneously permeabilized, extracted, and fixed with 10 °C
methanol for 5 min to eliminate soluble cytoplasmic epitopes
(b, right panel). Immunofluorescence analysis was
performed using mAb M3S1 directed against PDE4D (20 µg/ml),
affinity-purified rabbit polyclonal antibodies against RII (1 µg/ml) or RII (5 µg/ml, mAb CTR453) (13) (140 ng/ml), and
fluorescein isothiocyanate-labeled anti-mouse IgGs (green)
and TRITC-labeled anti-rabbit IgGs (red) in the second layer
(1:100 dilutions). Dual image overlays of PDE4D (green) and
RII (a, upper row, red) or RII
(a, lower row and b, red)
are shown. c, separate and merged images of centrosome
(CTR453; green) and RII (red) labeling. DNA
was stained with 0.1 µg/ml Hoechst 33342. Bars, 10 µm.
Representative observations from examination of many fields from three
or more experiments are presented.
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To further investigate the physical association of PDE4D and PKA type
II in the centrosomal region, Triton X-100-insoluble fractions from
cAMP-treated Sertoli cells were solubilized in RIPA buffer and
photoaffinity-labeled by 8-azido-[32P]cAMP to
visualize all R subunits. This approach demonstrated the presence of
specifically labeled RII (
and
) as well as RI (Fig.
3a, Input).
Addition of excess unlabeled cAMP in the photoaffinity reaction showed
specificity of labeling. Immunoprecipitation of photoaffinity-labeled
extracts with PDE4D-specific antibody (mAb M3S1) showed
co-precipitation of RII
and RII
but not RI, whereas no
precipitation was observed in controls with non-immune IgG (Fig.
3a, two right lanes). Conversely,
immunoprecipitation of both RII
and RII
co-precipitated PDE4D3
from RIPA extracts of cAMP-treated Sertoli cells (Fig. 3b
and not shown). No co-precipitation was observed in soluble fractions
containing only PDE4D2, indicating specificity of the interaction (Fig.
3c). In addition, immunoaffinity chromatography of
cytoskeletal extracts from FRTL-5 cells using an anti-PDE4D-specific
antibody retained RII together with PDE4D (not shown). These data
demonstrate that PDE4D3 and RII are in a complex probably located in
the centrosomal region. On the basis of the extraction data and
immunofluorescence observations, we cannot exclude localization of
PDE4D3 also in the Golgi, as shown in thyroid cells (15).

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Fig. 3.
PKA and PDE4D interact inside cells.
a, RIPA extracts from the insoluble fraction of Sertoli
cells treated with 8-CPTcAMP (100 µM, 16 h) were
prepared as described in the legend to Fig. 1. Cyclic AMP-binding
proteins were photoaffinity-labeled by incubation with 1 µM 8-azido-[32P]cAMP in the absence ( ) or
presence (+) of 100-fold excess cold competitor for 1 h on ice
followed by UV radiation at 254 nm for 10 min as described (32). Five
percent of the labeling reaction was directly subjected to SDS-PAGE and
autoradiography (Input). Immunoprecipitation was performed
by incubation of labeled extract (500 µg protein, 2.5 µg/µl) with
anti-PDE4D antibody (M3S1 mAb; 50 µg/ml) or non-immune mouse IgG
(IgG) for 2 h at 4 °C followed by incubation with
protein A/G beads (25 µl of 1:1 slush) for 16 h and four rounds
of washing of the precipitates before analysis together with Input.
b, immunoprecipitation was performed as above using RIPA
extracts (500 µg of protein, 2.5 µg/µl) and anti-RII mAb (25 µg/ml) or irrelevant mouse IgG (IgG). Immunoblot analysis
for PDE4D and RII was performed as in Fig. 1. Recombinant PDE4D3 was
used as standard (Std.). Mobility of molecular size markers
is indicated in kDa. c, immunoprecipitation was performed as
in panel b but using the PDE4D2-containing S200 fraction
from cAMP-treated cells (see Fig. 1) as source. Precipitates and
supernatant after immunoprecipitation were analyzed for the content of
PDE4D2. Recombinant PDE4D2 was used as standard (Std.).
Mobility of molecular size markers is indicated in kDa. A
representative of four (panels a and b) and two
(panel c) experiments is shown.
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The centrosomal region harbors a number of large structural proteins
that surround centrioles and participate in nucleation and
stabilization of microtubules in interphase and regulation of spindle
formation at mitosis (reviewed in Refs. 18, 19). Centrosomal proteins
that have been shown to anchor PKA include AKAP450 (also called
AKAP350, CG-NAP, Hyperion and yotiao), pericentrin, and in male germ
cells hAKAP220 (20-24). To explore the possibility that PDE4D and PKA
are tethered by a common anchoring protein, we examined whether PDE4D
is associated with AKAP450. Dual immunostaining of PDE4D and AKAP450
showed overlap of the two proteins in the centrosomal region (Fig.
4a), but not in the Golgi
region stained by several AKAP450 antibodies (20). As the epitope of
the centrosomal marker used for dual staining with PKA in Fig.
2c also maps to AKAP450,2 PKA is also
co-localized with the AKAP450·PDE4D complex in Sertoli cells.
Furthermore, PDE4D3 and PKA-RII
were detected in AKAP450 immune
precipitates from extracts of partially purified centrosome-nuclei complexes (Fig. 4b, upper panels). Conversely,
anti-PDE4D co-precipitated AKAP450 (lower panel). Finally,
expression of a soluble fragment of AKAP450 (amino acids 1710-2872)
fused to GFP-bound PDE4D3 as shown by co-immunoprecipitation of
GFP·AKAP450 and PDE4D3 when co-transfected into 293T cells (Fig.
4c). In contrast, overlapping fragments spanning the other
domains of AKAP450 did not associate with PDE4D3 when co-expressed (not
shown). The interaction between AKAP450 and PKA-RII
has been
previously demonstrated (20), and RII
, endogenously expressed in
293T cells, was co-precipitated with GFP·AKAP450 and PDE4D3 (Fig.
4c, lower panel) (21). Mutation of the RII
binding domain (L2556P) to abolish PKA binding (20) did not affect the
interaction of PDE4D3 with AKAP450, indicating that the interaction is
direct and not dependent on PKA (not shown).

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Fig. 4.
AKAP450 harbors a signaling unit consisting
of PKA and PDE4D. a, dual immunostaining of
PDE4D (M3S1 mAb, green, 20 µg/ml) and AKAP450 (a24
antibody, red, 6 µg/ml). Sertoli cells were prepared and
subjected to immunofluorescence as shown in Fig. 2. Image overlap is
shown (co-localization appears yellow). DNA was stained with
0.1 µg/ml Hoechst 33342. Bar: 10 µm. b,
precipitation of an AKAP450·PDE4D3·PKA complex was performed from
partially purified nuclei-centrosome complexes (33) extracted in a
buffer containing 5 mM Hepes, pH 7.9, 400 mM
NaCl, 26% glycerol, 1.5 mM MgCl2, 0.2 mM EDTA, 0.5 mM dithiothreitol, 0.5 mM PMSF (500 µg, 2.5 µg/ml) and using anti-AKAP450
antibody (a24, 30 µg/ml, upper panel) or anti-PDE4D
antibody (M3S1 mAb; 50 µg/ml, lower panel) and detected by
immunoblotting with indicated antibodies. c, PDE4D3 was
expressed together with a GFP-tagged fragment of AKAP450 (amino acids
1710-2872; see scheme in upper panel) expressed
at levels where the majority was soluble or together with GFP with no
fusion (pEGFP-N1, CLONTECH) in 293T cells. Cells
were lysed in isotonic buffer (150 mM NaCl, 50 mM Tris-Cl, pH 7.5, 1% Nonidet P-40, 2 mM
PMSF, and CompleteTM antiprotease mix), centrifuged to
remove insoluble material, and subjected to anti-GFP immunoblotting
(Input, left panels). Extracts containing equal
amounts of GFP·AKAP450/GFP (and PDE4D, not shown) were
immunoprecipitated with anti-GFP antibody (1:100 dilution) and analyzed
by Western blot for the presence of PDE4D and RII (right
panels). A representative of three experiments is shown.
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Collectively, the data presented here indicate the presence of a
signaling complex consisting of PKA and PDE both assembled via a common
anchoring protein. Because the components of this complex are present
at low levels in the insoluble fraction, the stoichiometry of the
complex is difficult to assess quantitatively. However, based on
examination of input lysates and supernatants following
immunoprecipitation, it appears that all the PDE4D3 and AKAP450 in the
RIPA fraction goes into a PDE4D3·PKA·AKAP450 complex, whereas a
part (5-20%) of PKA RII
and/or RII
is in a complex with AKAP450
and PDE4D3. This is consistent with earlier observations of PKA
associated with other cytoskeletal structures and other AKAPs in the
insoluble material.
Targeting of PKA and PDE in close proximity to the PKA substrate will
allow for a tight control of the phosphorylation state of proteins
regulated by cAMP signaling. Spatial control is achieved by targeting
of PKA. Temporal control and inactivation of the effect of cAMP on PKA
is accomplished by complexing of PDE at the same site (Fig.
5). It should also be noted that the
particular PDE4D3 variant that co-localizes with PKA RII can be
phosphorylated and activated by PKA. Therefore, the physical
association of PKA and PDE4D3 establishes a local feedback regulation
whereby cAMP activates PKA by dissociation of C, which in turn
phosphorylates and activates PDE4D3 (15). The resulting decrease in
cAMP causes reassociation of C and inactivation of PKA, rather than
diffusion of C into the cytoplasm. The proximity of PKA and PDE and
this rapid feedback mechanism indicate that the cAMP response may occur only in a confined compartment of the cell. Several AKAPs have been
shown to serve as anchoring proteins for multiple signal molecules to
form signaling complexes where signals can be modulated by
co-localization of PKA and protein phosphatases (25-27), or several
signals can be integrated by co-localization of e.g. PKA and
PKC (28, 29). The PKA·PDE complex facilitated by dual anchoring via
AKAP450 adds to this list and provides a way of modulating signal
intensity at the level of cAMP. Furthermore, the capacity of AKAP450 to
anchor PDE4D extends the functions of this large protein that has
already been shown to anchor PKA, protein kinase N, and PP1 (20, 22,
27). The fact that centrosomal PKA, at least in some cells, have a
co-targeted PDE suggests the importance of a tight regulation of the
phosphorylation state of centrosomal proteins, possibly implicated in
regulation of microtubule stability where cAMP has a distinct
regulatory effect (19, 30, 31). It will be interesting to determine
whether PKA and PDEs also co-localize at other sites of PKA action
where a tightly regulated mechanism of termination of the cAMP signal is important.

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Fig. 5.
Model of the PKA-PDE signal complex depicts
the following steps. The effect of cAMP is mediated by PKA
phosphorylation of substrate proteins (step 1). PKA
phosphorylates and activates the PDE4D3 (step 2), and the
co-localized and now activated PDE4D3 degrades cAMP and terminates the
signal (step 3).
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ACKNOWLEDGEMENT |
We thank Dr. Guy Keryer (Curie Institute,
Paris, France) for discussions and critical reading of the manuscript.
 |
FOOTNOTES |
*
This work was supported by grants from the Norwegian Cancer
Society, the Norwegian Research Council, Anders Jahre's Foundation for
the Promotion of Science, NOVO Nordic Research Foundation Committee,
and by National Institutes of Health Grant HD20778 (to M. C.).The costs of publication of this
article were defrayed in part by the
payment of page charges. The article
must therefore be hereby marked
"advertisement" in
accordance with 18 U.S.C. Section
1734 solely to indicate this fact.
To whom correspondence should be addressed: Inst. of Medical
Biochemistry, University of Oslo, P. O. Box 1112 Blindern, N-0317 Oslo, Norway. Tel.: 47 22 85 14 54; Fax: 47 22 85 14 97; E-mail: kjetil.tasken@basalmed.uio.no.
Published, JBC Papers in Press, April 2, 2001, DOI 10.1074/jbc.C000911200
2
W. A. Kemmner, unpublished observations.
 |
ABBREVIATIONS |
The abbreviations used are:
PKA, cAMP-dependent protein kinase;
PDE, phosphodiesterase;
PMSF, phenylmethylsulfonyl fluoride;
RIPA, radioimmune precipitation
buffer;
Ab, antibody;
GFP, green fluorescent protein.
 |
REFERENCES |
1.
|
Skålhegg, B. S.,
and Taskén, K.
(2000)
Front. Biosci.
5,
D678-D693[Medline]
[Order article via Infotrieve]
|
2.
|
Conti, M.,
and Jin, S. L.
(1999)
Prog. Nucleic Acids Res. Mol. Biol.
63,
1-38[Medline]
[Order article via Infotrieve]
|
3.
|
Colledge, M.,
and Scott, J. D.
(1999)
Trends Cell Biol.
9,
216-221[CrossRef][Medline]
[Order article via Infotrieve]
|
4.
|
Verde, I.,
Pahlke, G.,
Salanova, M.,
Zhang, G.,
Wang, S.,
Coletti, D.,
Onuffer, J.,
Jin, S. L.,
and Conti, M.
(2001)
J. Biol. Chem.
276,
11189-11198[Abstract/Free Full Text]
|
5.
|
Yarwood, S. J.,
Steele, M. R.,
Scotland, G.,
Houslay, M. D.,
and Bolger, G. B.
(1999)
J. Biol. Chem.
274,
14909-14917[Abstract/Free Full Text]
|
6.
|
Øyen, O.,
Frøysa, A.,
Sandberg, M.,
Eskild, W.,
Joseph, D.,
Hansson, V.,
and Jahnsen, T.
(1987)
Biol. Reprod.
37,
947-956[Abstract]
|
7.
|
Collas, P.,
Courvalin, J. C.,
and Poccia, D.
(1996)
J. Cell Biol.
135,
1715-1725[Abstract]
|
8.
|
Collas, P.,
Le Guellec, K.,
and Taskén, K.
(1999)
J. Cell Biol.
147,
1167-1180[Abstract/Free Full Text]
|
9.
|
Iona, S.,
Cuomo, M.,
Bushnik, T.,
Naro, F.,
Sette, C.,
Hess, M.,
Shelton, E. R.,
and Conti, M.
(1998)
Mol. Pharmacol.
53,
23-32[Abstract/Free Full Text]
|
10.
|
Eide, T.,
Coghlan, V.,
Ørstavik, S.,
Holsve, C.,
Solberg, R.,
Skålhegg, B. S.,
Lamb, N. J.,
Langeberg, L.,
Fernandez, A.,
Scott, J. D.,
Jahnsen, T.,
and Taskén, K.
(1998)
Exp. Cell Res.
238,
305-316[CrossRef][Medline]
[Order article via Infotrieve]
|
11.
|
Vang, T.,
Torgersen, K. M.,
Sundvold, V.,
Saxena, M.,
Levy, F. O.,
Skalhegg, B. S.,
Hansson, V.,
Mustelin, T.,
and Taskén, K.
(2001)
J. Exp. Med.
193,
497-508[Abstract/Free Full Text]
|
12.
|
Keryer, G.,
Skalhegg, B. S.,
Landmark, B. F.,
Hansson, V.,
Jahnsen, T.,
and Taskén, K.
(1999)
Exp. Cell Res.
249,
131-146[CrossRef][Medline]
[Order article via Infotrieve]
|
13.
|
Bailly, E.,
Doree, M.,
Nurse, P.,
and Bornens, M.
(1989)
EMBO J.
8,
3985-3995[Abstract]
|
14.
|
Vicini, E.,
and Conti, M.
(1997)
Mol. Endocrinol.
11,
839-850[Abstract/Free Full Text]
|
15.
|
Jin, S. L.,
Bushnik, T.,
Lan, L.,
and Conti, M.
(1998)
J. Biol. Chem.
273,
19672-19678[Abstract/Free Full Text]
|
16.
|
Landmark, B. F.,
Fauske, B.,
Eskild, W.,
Skålhegg, B. S.,
Lohmann, S. M.,
Hansson, V.,
Jahnsen, T.,
and Beebe, S. J.
(1991)
Endocrinology
129,
2345-2354[Abstract]
|
17.
|
Taskén, K. A.,
Knutsen, H. K.,
Attramadal, H.,
Taskén, K.,
Jahnsen, T.,
Hansson, V.,
and Eskild, W.
(1991)
Mol. Endocrinol.
5,
21-28[Abstract]
|
18.
|
Tassin, A. M.,
and Bornens, M.
(1999)
Biol. Cell
91,
343-354[CrossRef][Medline]
[Order article via Infotrieve]
|
19.
|
Fernandez, A.,
Cavadore, J. C.,
Demaille, J.,
and Lamb, N. J.
(1995)
Prog. Cell Cycle Res.
1,
241-253[Medline]
[Order article via Infotrieve]
|
20.
|
Witczak, O.,
Skalhegg, B. S.,
Keryer, G.,
Bornens, M.,
Taskén, K.,
Jahnsen, T.,
and Orstavik, S.
(1999)
EMBO J.
18,
1858-1868[Abstract/Free Full Text]
|
21.
|
Schmidt, P. H.,
Dransfield, D. T.,
Claudio, J. O.,
Hawley, R. G.,
Trotter, K. W.,
Milgram, S. L.,
and Goldenring, J. R.
(1999)
J. Biol. Chem.
274,
3055-3066[Abstract/Free Full Text]
|
22.
|
Takahashi, M.,
Shibata, H.,
Shimakawa, M.,
Miyamoto, M.,
Mukai, H.,
and Ono, Y.
(1999)
J. Biol. Chem.
274,
17267-17274[Abstract/Free Full Text]
|
23.
|
Diviani, D.,
Langeberg, L. K.,
Doxsey, S. J.,
and Scott, J. D.
(2000)
Curr. Biol.
10,
417-420[CrossRef][Medline]
[Order article via Infotrieve]
|
24.
|
Reinton, N.,
Collas, P.,
Haugen, T. B.,
Skålhegg, B. S.,
Hansson, V.,
Jahnsen, T.,
and Taskén, K.
(2000)
Dev. Biol.
223,
194-204[CrossRef][Medline]
[Order article via Infotrieve]
|
25.
|
Coghlan, V. M.,
Perrino, B. A.,
Howard, M.,
Langeberg, L. K.,
Hicks, J. B.,
Gallatin, W. M.,
and Scott, J. D.
(1995)
Science
267,
108-111[Medline]
[Order article via Infotrieve]
|
26.
|
Schillace, R. V.,
and Scott, J. D.
(1999)
Curr. Biol.
9,
321-324[CrossRef][Medline]
[Order article via Infotrieve]
|
27.
|
Westphal, R. S.,
Tavalin, S. J.,
Lin, J. W.,
Alto, N. M.,
Fraser, I. D.,
Langeberg, L. K.,
Sheng, M.,
and Scott, J. D.
(1999)
Science
285,
93-96[Abstract/Free Full Text]
|
28.
|
Klauck, T. M.,
Faux, M. C.,
Labudda, K.,
Langeberg, L. K.,
Jaken, S.,
and Scott, J. D.
(1996)
Science
271,
1589-1592[Abstract]
|
29.
|
Nauert, J. B.,
Klauck, T. M.,
Langeberg, L. K.,
and Scott, J. D.
(1997)
Curr. Biol.
7,
52-62[Medline]
[Order article via Infotrieve]
|
30.
|
Gavet, O.,
Ozon, S.,
Manceau, V.,
Lawler, S.,
Curmi, P.,
and Sobel, A.
(1998)
J. Cell Sci.
111,
3333-3346[Abstract/Free Full Text]
|
31.
|
Gradin, H. M.,
Larsson, N.,
Marklund, U.,
and Gullberg, M.
(1998)
J. Cell Biol.
140,
131-141[Abstract/Free Full Text]
|
32.
|
Walter, U.,
and Greengard, P.
(1983)
Methods Enzymol.
99,
154-162[Medline]
[Order article via Infotrieve]
|
33.
|
Maro, B.,
and Bornens, M.
(1980)
Biol. Cellulaire
39,
287-290
|
34.
|
Dorrington, J. H.,
Rolles, N. F.,
and Fritz, I. B.
(1975)
Mol. Cell. Endocrinol.
3,
57-70[CrossRef][Medline]
[Order article via Infotrieve]
|
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