ACCELERATED PUBLICATION
A Novel Glucokinase Regulator in Pancreatic
Cells
PRECURSOR OF PROPIONYL-CoA CARBOXYLASE
SUBUNIT INTERACTS
WITH GLUCOKINASE AND AUGMENTS ITS ACTIVITY*
Akihiko
Shiraishi
§,
Yuichiro
Yamada
,
Yoshiyuki
Tsuura
,
Shimpei
Fijimoto
,
Katsushi
Tsukiyama
,
Eri
Mukai
,
Yukiyasu
Toyoda¶,
Ichitomo
Miwa¶, and
Yutaka
Seino
From the
Department of Metabolism and Clinical
Nutrition, Graduate School of Medicine, Kyoto University, Sakyoku,
Kyoto 606-8507 and the ¶ Department of Pathobiochemistry,
Faculty of Pharmacy, Meijo University,
Tempaku-ku, Nagoya 468-8503, Japan
Received for publication, August 7, 2000, and in revised form, November 11, 2000
 |
ABSTRACT |
A glucokinase regulatory protein has been
reported to exist in the liver, which suppresses enzyme activity in a
complex with fructose 6-phosphate, whereas no corresponding protein has
been found in pancreatic
cells. To search for such a protein in
pancreatic
cells, we screened for a cDNA library of the HIT-T15
cell line with the cDNA of glucokinase from rat islet by the
yeast two hybrid system. We detected a cDNA encoding the
precursor of propionyl-CoA carboxylase
subunit (p
PCCase), and
glutathione S-transferase pull-down assay
illustrated that p
PCCase interacted with recombinant rat islet
glucokinase and with glucokinase in rat liver and islet extracts.
Functional analysis indicated that p
PCCase decreased the
Km value of recombinant islet glucokinase for
glucose by 18% and increased Vmax value by
23%. We concluded that p
PCCase might be a novel activator of
glucokinase in pancreatic
cells.
 |
INTRODUCTION |
Glucose phosphorylation is known to be the rate-limiting
step in glycolysis of pancreatic
cells (1). This step is catalyzed by hexokinase through a low Km pathway and by
glucokinase through a high Km pathway (2, 3).
Glucokinase predominantly regulates intracellular glucose metabolism
when ambient glucose concentration is increased (4), and the reduced
activity of this enzyme has been reported to decrease glucose-induced
insulin release (5). Glucokinase is also expressed in the liver, which is another regulatory center of glucose homeostasis. Van Schaftingen et al. (6) have reported that the rat liver contains a
regulatory protein that binds to glucokinase, and the activity of
glucokinase coupled to this protein is thought to be mediated by
competitive binding of fructose 6-phosphate and fructose 1-phosphate in
the liver (6, 7). Thus, this feedback regulation may affect the balance
of glycolysis and gluconeogenesis. There have also been attempts to
find a corresponding protein in pancreatic islets (8). Fructose
1-phosphate converted from fructose was reported to enhance glucokinase
activity in vitro (9), and a greater increase in glucokinase
activity has been reported in extracts from islets overexpressing
glucokinase without an increase of glucose utilization (10).
These reports suggested the existence of a factor capable of regulating
glucokinase activity or its affinity for glucose under physiological
intracellular conditions, although as yet, no direct evidence for such
a molecule has been reported. To clarify whether a glucokinase
regulatory protein is present in pancreatic islets, we screened for a
cDNA library of the HIT-T15 cell line with the cDNA of
glucokinase from rat pancreatic
cells using the yeast two hybrid
system and found a novel binding regulator for glucokinase.
 |
EXPERIMENTAL PROCEDURES |
cDNA Cloning--
Rat pancreatic islet glucokinase
full-length cDNA was amplified by polymerase chain reaction
(PCR)1 using pancreatic
cell glucokinase-specific oligonucleotides (11). This cDNA was
subcloned into the following two types of plasmids: pBTM116, the
"bait" for yeast two hybrid screen (pBTM116-GK), and pGEX4T-1
(Amersham Pharmacia Biotech) to produce glutathione S-transferase (GST)-fused glucokinase (GST-GK). Full-length
cDNA of precursor of propionyl-CoA carboxylase
subunit
(p
PCCase) in pancreatic islet was also amplified from rat pancreatic
islets cDNA by PCR using the oligonucleotides for rat liver
p
PCCase (12).
Recombinant Protein--
Rat pancreatic islet glucokinase and
p
PCCase were subcloned into pGEX4T-1 and transformed into
Escherichia coli strain M15. Following induction of
protein expression with isopropyl thio-
-D-galactosidase, the GST fusion proteins were purified according to the manufacturer's instructions (Amersham Pharmacia Biotech) (13). The produced protein
was dissolved in 50 mM Tris-HCl, pH 8.0. Recombinant
glucokinase without GST tag (rGK) was made by thrombin cleavage
according to the manufacturer's instruction.
Screening for the cDNA Encoding a Protein with Affinity for
Rat Islet Glucokinase by the Yeast Two Hybrid System--
Yeast two
hybrid screening was performed as described previously (14). The bait
plasmid was pBTM116-GK, in which rat pancreatic
cell glucokinase
was fused to the LexA DNA-binding domain. The yeast strain L40 (MATa
trp1 leu2 his3 LYS2::lexA-HIS3 URA3::lexA-LacZ) was
transformed with pBTM116-GK using the lithium acetate method (15).
Strain L40 carrying pBTM116-GK was transformed with a HIT-T15 (hamster
pancreatic
cell line (16)) cell cDNA library. Approximately
1.0 × 106 transformants were screened for growth on
Yc plate medium (2% glucose, 0.5% ammonium sulfate, 1% succinic
acid, and 0.12% yeast nitrogen base) containing 0.5 mM
3-amino-1,2,4-triazole but lacking tryptophan, histidine, uracil, and
leucine. His+ colonies were then placed on paper filters
and stained with
5-bromo-4-chloro-3-indolyl-
-D-galactopyranoside for
-galactosidase activity as described (15). Two His+ and
LacZ+ clones were obtained with this screening. The
plasmids were transformed to E. coli and isolated.
Preparation of Rat Pancreatic Islet and Liver
Extract--
Pancreatic islets were isolated from male Wistar rats by
collagenase digestion as described previously (17) and were then sonicated in RIPA (150 mM NaCl, 1.0% Nonidet P-40, 50 mM Tris-HCl, pH 8.0). The homogenate was centrifuged at
10,000 × g for 15 min at 4 °C, and the supernatant
was collected as the islet extract. Rat liver tissue was also
homogenized in RIPA, and the supernatant was collected after
centrifugation at 10,000 × g for 15 min at 4 °C as
liver extract.
Preparation of Islet Cellular Fractions--
Sucrose gradient
fractionation was performed for collected islets by the previously
described method (18). Islets in the 0.25 M sucrose were
homogenized in a Potter-Elvehjem homogenizer with 6 strokes of a
close-fitting Teflon pestle. The mixture was centrifuged for 10 min at
600 × g. The pellet was further purified by the method
of Blobel-Potter to obtain the purified nuclear fraction (19). The
supernatant was centrifuged for 10 min at 8,000 × g.
The pellet was collected as the mitochondrial fraction, and the
supernatant was centrifuged for 60 min at 105,000 × g. The resultant pellet was the microsomal fraction, and the supernatant was the cytosolic fraction. Each subcellular fraction was analyzed by
SDS-PAGE and Western blotting with anti-p
PCCase serum as described previously (13). The anti-p
PCCase serum was made from a rabbit immuned with GST-p
PCCase.
In Vitro Protein Interaction Assays--
GST pull-down assay was
performed as described previously (13). Each assay contained GST fusion
protein immobilized on glutathione-Sepharose beads (Amersham Pharmacia
Biotech). Briefly, samples containing glucokinase (5 µg of rGK, rat
pancreatic islet extract, or liver extract) were incubated with 3 µg
of GST (molecular mass, 27 kDa) or 9 of µg GST-p
PCCase
(molecular mass, 89 kDa) or 8 µg of GST-GK (molecular mass, 79 kDa)
in binding buffer (20 mM Tris-HCl, pH 7.6, 0.1 mM EDTA, 20% glycerol, 300 mM KCl, 0.1%
Nonidet P-40, 0.5 mM phenylmethylsulfonyl fluoride, 2 mM MgCl2, and 5 mM
2-mercaptoethanol) for 1 h at 4 °C. After incubation, the beads
were washed five times with binding buffer (10-fold volume of beads)
and resuspended in elution buffer (binding buffer containing 10 mM reduced glutathione). The bound proteins were resolved
by 10% SDS-PAGE and visualized by Western blotting with rabbit
anti-glucokinase antibody or anti-p
PCCase serum as described
previously (13, 20).
Assay for Glucokinase Activity--
Glucokinase enzyme activity
was measured by a fluorometric assay according to the method reported
previously (21). Glucokinase activity was measured as the fluorescence
of NADPH at excitation and emission wavelengths of 340 and 450 nm,
respectively. The reaction was performed in a solution consisting of 50 mM HEPES-NaOH, pH 7.4, 100 mM KCl, 8 mM MgCl2, 0.5 mM NADP, 1 mM dithiothreitol, 1 unit/ml of glucose 6-phosphate
dehydrogenase, ATP at various concentrations, and 0.2 µg/ml of GST-GK
supplemented with various concentrations of glucose at 37 °C for
half an hour and was stopped by addition of stop solution (300 mM NaH2PO4, 0.46 mM
sodium dodecylsulfate, pH 8.0). Reagent blanks were incubated in the
absence of ATP and were subtracted from the total fluorescence of the
corresponding complete reaction mixtures. The Km,
Vmax, and Hill coefficient were determined by
the nonlinear least squares routine to fit the Hill equation using
Sigma Plot (1, 9).
Statistical Analysis--
All data are expressed as means ± S.E., with n values being the number of experiments
performed. Statistical significance was determined by paired Student's
t test.
 |
RESULTS |
The yeast two hybrid system was used to identify cDNAs in the
HIT-T15 cell cDNA library encoding the regulatory protein using the
bait plasmid pBTM116-GK. The resultant cDNA insert was isolated by
nutritional selection and
-galactosidase activity and was shown to
be 68% of the rat liver p
PCCase gene by sequence analysis. The
full-length cDNA of p
PCCase was obtained from rat pancreatic islet cDNA by a PCR-based method. The specificity of the
interaction between pancreatic islet glucokinase and pancreatic islet
p
PCCase was tested in vitro. The GST-fused p
PCCase
(GST-p
PCCase) could bind to rGK and glucokinase in cellular extracts
of rat pancreatic islets and liver (Fig.
1). Furthermore, the GST-fused
glucokinase (GST-GK) could bind to p
PCCase in cellular extracts of
rat pancreatic islets (Fig. 1D).

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Fig. 1.
Interaction of
p PCCase with GK. A,
interaction of GST-p PCCase with recombinant GK. B,
interaction of GST-p PCCase with cellular extract of pancreatic
islets. C, interaction of GST-p PCCase with cellular
extract of liver. D, interaction of GST-GK with cellular
extract of pancreatic islets. GST-p PCCase interacted with GK, and
GST-GK interacted with p PCCase in vitro. GST or
GST-p PCCase, immobilized on glutathione beads, was incubated with
recombinant GK, rat pancreatic islet, or liver cellular extract. GST-GK
immobilized on glutathione beads was also incubated with islet extract.
Bound proteins were detected with anti-GK antibodies or anti-p PCCase
serum.
|
|
Western blotting was performed to confirm the subcellular localization
of p
PCCase in islets. p
PCCase was shown to be present in the
mitochondrial fraction and cytosolic fraction, but it was not
detected in the microsomal or nuclear fractions (Fig.
2).

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Fig. 2.
p PCCase in various
islet cell fractions. Western blotting with anti-p PCCase
serum is shown. p PCCase was visualized in the cytosolic fraction and
mitochondrial fraction. Each lane contained 1 µg of
protein.
|
|
Next, the effects of GST-p
PCCase on glucokinase activity were
investigated. When 25 µg/ml GST-p
PCCase was added, GST-GK activity
was significantly higher than that in controls within the range of 3 to
50 mM glucose (Fig.
3A), whereas the GST tag alone
did not show any effect on GST-GK activity (data not shown). GST-p
PCCase had no activity of hexokinase or glucokinase. The glucokinase inhibitor mannoheptulose at 20 mM suppressed
the activity of GST-GK by 67 or 60% in the presence or absence of
p
PCCase, respectively, when the activity was assayed in the presence
of 10 mM glucose and 5 mM ATP. The
Vmax value of GST-GK for glucose was increased
by about 23%, and the Km value was reduced by 18%
when GST-p
PCCase was added (Table I).
The Hill number was 1.8 in the presence of GST-p
PCCase, which was
not significantly different from the value of 1.7 in controls (Table
I). Furthermore, the Km value of GST-GK for ATP was
not affected by addition of GST-p
PCCase (see Fig. 3B and
Table I). The activity of GST-GK was increased in a GST-p
PCCase
concentration-dependent manner (Fig. 3C). In the
previous reports, palmitoyl-CoA has been shown to suppress glucokinase
activity at higher concentrations beyond physiological ones (22-24).
We tested the effects of p
PCCase on glucokinase activity in the
presence or absence of palmitoyl-CoA and propionyl-CoA. The activating
effect of GST-p
PCCase was not influenced by the presence of 3 µM palmitoyl-CoA and 3 µM propionyl-CoA (data not shown).

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Fig. 3.
Effects of p PCCase
on GK activity. A, reaction velocity of
GST-GK (closed circles) or GST-GK + 25 mg/ml GST-p PCCase
(open circles) with glucose concentrations from 0.05 to 50 mM at 5 mM ATP (n = 5).
B, reaction velocity of GST-GK (closed circles)
or GST-GK + GST-p PCCase (open circles) with ATP
concentrations from 0.01 to 10 mM at 5 mM
glucose (n = 4). C, reaction velocity of GK
with various concentrations of p PCCase (up to 30 µg/ml) at 10 mM glucose and 5 mM ATP (n = 5). Values shown are means ± S.E. from four or five independent
experiments. * indicates p < 0.01 (or 0.05)
versus each control value.
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Table I
Kinetic parameters of GST-GK activity in the presence or absence of
GST-p PCCase
h, Hill coefficient number; NS, not significant. The data
are expressed as means ± S.E. Km,
Vmax, and h were calculated from six
independent experiments, and Km(ATP) was
calculated from four independent experiments.
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|
 |
DISCUSSION |
In this study, we found that p
PCCase, which is present in the
cytosolic compartment (25-27), unexpectedly interacted with pancreatic
islet glucokinase and activated its enzyme activity with increased
Vmax and decreased Km values
for glucose.
Liver and pancreatic
cells play crucial roles in glucose
homeostasis, but they have distinctive functions (28). In the liver, in
response to changes in plasma glucose concentration, hepatic glucose
uptake and glucose output are alternatively increased to maintain the
plasma glucose concentration. Accordingly, an abrupt alteration of
ambient glucose concentration might require a negative feedback loop
for glucokinase activity by binding of a regulatory protein coupled to
fructose 6-phospate (6, 29). On the other hand, pancreatic
cells
secrete insulin in response to increasing glucose concentration (4). A
glucose-induced insulin secretion is subject to intracellular glucose
metabolism, and in
cells glucose metabolism unidirectionally flows
toward the direction of ATP production with the metabolic
characteristic of development of a glycerol phosphate shuttle (30),
lack of fructose-bisphosphatase (31), and a low activity of lactate dehydrogenase (32). However, a positive regulator of glucokinase, which
has the lowest activity among all the glycolytic enzymes, had not been
found in pancreatic
cells. In the present study, we demonstrated
that p
PCCase increased Vmax of glucokinase
for glucose and reduced Km. Such regulation may
enable maximal enhancement of glucose metabolism in the range of
physiological ambient glucose concentrations.
p
PCCase is a precursor of the
subunit in propionyl-CoA
carboxylase (PCCase), a biotin-dependent enzyme that is
present in the matrix of mitochondria (25-27). p
PCCase protein
(61.5 kDa) is known to be synthesized on cytoplasmic polyribosomes and
transferred to the mitochondria via a specific transporter. After
arrival at the mitochondrial matrix, p
PCCase is processed to mature
subunit of propionyl-CoA carboxylase protein (54 kDa) by a
Zn2+-dependent proteolytic component in the
matrix (27). Thus, p
PCCase could exist in the cytoplasmic
compartment. The importance of the regulation of glucokinase activity
by p
PCCase remains to be determined. Pancreatic
cells are
continuously exposed to not only glucose but also fatty acids, which
are known to affect glucose-induced insulin secretion (33, 34).
Palmitate and oleate are strong potentiators of glucose-induced insulin
release (35, 36), and Liu et al. (33) reported that glucose
utilization examined using [2H]glucose was augmented
accompanied by a decrease in the level of glucose 6-phosphate in islets
cultured with oleate. These findings seemed to be consistent with the
hypothesis that a precursor of PCCase
subunit, which exists in the
cytosolic compartment and is known to become as functional as PCCase in
fatty acid metabolism in the mitochondrial matrix (36, 37), enhances
the glycolytic pathway by up-regulating glucokinase activity. This
hypothesis might be applicable to the glucose metabolism in the liver.
In addition, p
PCCase might contribute to the localization of
glucokinase by transporting the coupled enzyme in the liver and
pancreatic
cells.
In conclusion, p
PCCase has been shown to be a novel activator of
glucokinase. Unlike the binding regulatory protein in the liver (7, 6),
p
PCCase alters the Km and
Vmax values of glucokinase for glucose,
resulting in enhanced enzyme activity in islets. Because glucokinase is
a rate-limiting enzyme (28), p
PCCase may be directly involved in the
regulation of glucose metabolism and glucose-induced insulin secretion
in pancreatic islets.
 |
ACKNOWLEDGEMENTS |
We thank Susumu Seino of Chiba University
Graduate School of Medicine for arranging the yeast two hybrid
screening system.
 |
FOOTNOTES |
*
This study was supported in part by grants-in-aid for
Scientific Research from the Ministry of Education, Science, Sports and
Culture of Japan, Grant-in-Aid for Creative Basic Research 10NP0201
from the Ministry of Education, Science, Sports and Culture of Japan,
and grants from the Research for the Future Program of the Japan
Society for the Promotion of Science (JSPS-RFTF97I00201).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: Dept. of Metabolism and
Clinical Nutrition, Graduate School of Medicine, Kyoto University,
54 Shogoin-Kawahara-cho, Sakyoku, Kyoto 606-8507, Japan. Tel.:
81-75-751-3560; Fax: 81-75-751-4244; E-mail:
siraisi@metab.kuhp. kyoto-u.ac.jp.
Published, JBC Papers in Press, November 20, 2000, DOI 10.1074/jbc.C000530200
 |
ABBREVIATIONS |
The abbreviations used are:
PCR, polymerase chain reaction;
GST, glutathione S-transferase;
GK, glucokinase;
p
PCCase, precursor of propionyl-CoA carboxylase
subunit;
r, recombinant;
PCCase, propionyl-CoA carboxylase.
 |
REFERENCES |
1.
|
Matschinsky, F. M.,
Glaser, B.,
and Magnuson, M. A.
(1998)
Diabetes
47,
307-315[Abstract]
|
2.
|
Xu, L. Z.,
Harrison, R. W.,
Weber, I. T.,
and Pilkis, S. J.
(1995)
J. Biol. Chem.
270,
9939-9946[Abstract/Free Full Text]
|
3.
|
Schuit, F.,
Moens, K.,
Heimberg, H.,
and Pipeleers, D.
(1999)
J. Biol. Chem.
274,
32803-32809[Abstract/Free Full Text]
|
4.
|
Matschinsky, F. M.,
and Collins, H. W.
(1997)
Chem. Biol.
4,
249-257[Medline]
[Order article via Infotrieve]
|
5.
|
Wang, H.,
and Iynedjian, P. B.
(1997)
Proc. Natl. Acad. Sci. U. S. A.
94,
4372-4377[Abstract/Free Full Text]
|
6.
|
van Schaftingen, E.,
Detheux, M.,
and da Cunha Veiga, M.
(1994)
FASEB J.
8,
414-419[Abstract/Free Full Text]
|
7.
|
Vandercammen, A.,
and van Schaftingen, E.
(1990)
Eur. J. Biochem.
191,
483-489[Abstract]
|
8.
|
Tiedge, M.,
Steffeck, H.,
Elsner, M.,
and Lenzen, S.
(1999)
Diabetes
48,
514-523[Abstract]
|
9.
|
Malaisse, W. J.,
Malaisse-Lagae, F.,
Davies, D. R.,
Vandercammen, A.,
and van Schaftingen, E.
(1990)
Eur. J. Biochem.
190,
539-545[Abstract]
|
10.
|
Becker, T. C.,
Noel, R. J.,
Johnson, J. H.,
Lynch, R. M.,
Hirose, H.,
Tokuyama, Y.,
Bell, G. I.,
and Newgard, C. B.
(1996)
J. Biol. Chem.
271,
390-394[Abstract/Free Full Text]
|
11.
|
Magnuson, M. A.,
and Shelton, K. D.
(1989)
J. Biol. Chem.
264,
15936-15942[Abstract/Free Full Text]
|
12.
|
Kraus, J. P.,
Firgaira, F.,
Novotny, J.,
Kalousek, F.,
Williams, K. R.,
Williamson, C.,
Ohura, T.,
and Rosenberg, L. E.
(1986)
Proc. Natl. Acad. Sci. U. S. A.
83,
8049-8053[Abstract]
|
13.
|
Inada, A.,
Someya, Y.,
Yamada, Y.,
Ihara, Y.,
Kubota, A.,
Ban, N.,
Watanabe, R.,
Tsuda, K.,
and Seino, Y.
(1999)
J. Biol. Chem.
274,
21095-21103[Abstract/Free Full Text]
|
14.
|
Kotake, K.,
Ozaki, N.,
Mizuta, M.,
Sekiya, S.,
Inagaki, N.,
and Seino, S.
(1997)
J. Biol. Chem.
272,
29407-29410[Abstract/Free Full Text]
|
15.
|
Vojtek, A. B.,
Hollenberg, S. M.,
and Cooper, J. A.
(1993)
Cell
74,
205-214[Medline]
[Order article via Infotrieve]
|
16.
|
Ashcroft, S. J.,
Hammonds, P.,
and Harrison, D. E.
(1986)
Diabetologia
29,
727-733[Medline]
[Order article via Infotrieve]
|
17.
|
Kajikawa, M.,
Ishida, H.,
Fujimoto, S.,
Mukai, E.,
Nishimura, M.,
Fujita, J.,
Tsuura, Y.,
Okamoto, Y.,
Norman, A. W.,
and Seino, Y.
(1999)
Endocrinology
140,
4706-4712[Abstract/Free Full Text]
|
18.
|
Hogebon, G. H.
(1955)
Methods Enzymol.
1,
16-19
|
19.
|
Blobel, G.,
and Van Potter, R.
(1966)
Science
154,
1662-1664[Medline]
[Order article via Infotrieve]
|
20.
|
Toyoda, Y.,
Miwa, I.,
Kamiyama, M.,
Ogiso, S.,
Okuda, J.,
and Nonogaki, T.
(1995)
FEBS Lett.
359,
81-84[CrossRef][Medline]
[Order article via Infotrieve]
|
21.
|
Miwa, I.,
Mita, Y.,
Murata, T.,
Okuda, J.,
Sugiura, M.,
Hamada, Y.,
and Chiba, T.
(1995)
Enzyme Protein
48,
135-142
|
22.
|
Tippett, P. S.,
and Neet, K. E.
(1982)
J. Biol. Chem.
257,
12839-12845[Free Full Text]
|
23.
|
Tippett, P. S.,
and Neet, K. E.
(1982)
J. Biol. Chem.
257,
12846-12852[Free Full Text]
|
24.
|
Printz, R. L.,
Magnuson, M. A.,
and Granner, D. K.
(1993)
Annu. Rev. Nutr.
13,
463-496[CrossRef][Medline]
[Order article via Infotrieve]
|
25.
|
Browner, M. F.,
Taroni, F.,
Sztul, E.,
and Rosenberg, L. E.
(1989)
J. Biol. Chem.
264,
12680-12685[Abstract/Free Full Text]
|
26.
|
Moss, J.,
and Lane, M. D.
(1971)
Adv. Enzymol.
35,
321-342[Medline]
[Order article via Infotrieve]
|
27.
|
Kraus, J. P.,
Kalousek, F.,
and Rosenberg, L. E.
(1983)
J. Biol. Chem.
258,
7245-7248[Abstract/Free Full Text]
|
28.
|
Matschinsky, F. M.
(1990)
Diabetes
39,
647-652[Abstract]
|
29.
|
Siota, C.,
Coffey, J.,
Grimsby, J.,
Grippo, J. F.,
and Magnuson, M. A.
(1999)
J. Biol. Chem.
274,
37125-37130[Abstract/Free Full Text]
|
30.
|
MacDonald, M. J.
(1981)
J. Biol. Chem.
256,
8287-8290[Abstract/Free Full Text]
|
31.
|
Sener, A.,
and Malaisse, W. J.
(1978)
Diabetes Metab.
4,
127-133
|
32.
|
Sekine, N.,
Cirulli, V.,
Regazzi, R.,
Brown, L. J.,
Gine, E.,
Tamarit-Rodriguez, J.,
Girotti, M.,
Marie, S.,
MacDonald, M. J.,
and Wollheim, C. B.
(1994)
J. Biol. Chem.
269,
4895-4902[Abstract/Free Full Text]
|
33.
|
Liu, Y. Q.,
Tornheim, K.,
and Leahy, J. L.
(1998)
J. Clin. Invest.
101,
1870-1875[Abstract/Free Full Text]
|
34.
|
Unger, R. H.
(1995)
Diabetes
44,
863-870[Abstract]
|
35.
|
Hosokawa, H.,
Corkey, B. E.,
and Leahy, J. L.
(1997)
Diabetologia
40,
392-397[CrossRef][Medline]
[Order article via Infotrieve]
|
36.
|
Warnotte, C.,
Gilon, P.,
Nenquin, M.,
and Henquin, J. C.
(1994)
Diabetes
43,
703-711[Abstract]
|
37.
|
Scholte, H. R.
(1969)
Biochim. Biophys. Acta
178,
137-144[Medline]
[Order article via Infotrieve]
|
Copyright © 2001 by The American Society for Biochemistry and Molecular Biology, Inc.