In Dictyostelium discoideum Ax-2 cells, a specific checkpoint (PS point) from which cells enter the differentiation phase in response to starvation has been specified in the cell cycle. Using the differential display method, we isolated a novel gene, dia1 (differentiation-associated gene 1), that is specifically expressed in cells differentiating from the PS point. The dia1 mRNA has an open reading frame of 1,368 bp and is deduced to code for a 48.6 kDa protein (DIA1). The DIA1 protein is highly serine-rich and the serine residues are predominantly located in the C-terminal region. After the PSORT II search, the protein is predicted to be GPI-anchored at the plasma membrane. Unexpectedly, dia1 overexpression rather impaired the progression of differentiation, possibly coupled with the reduced expression of early genes such as cAMP receptor1 (car1). The inhibitory effect of dia1 expression on early differentiation was almost completely nullified by externally applied cAMP pulses. In contrast to dia1 overexpression, antisense RNA-mediated dia1 inactivation was found to enhance the initial step of cell differentiation, as exemplified by precocious expression of car1 and other early genes. We discuss the unique structure and function of DIA1 in relation to the cooperative development of cells during the establishment of multicellular organization.

Abe
F.
,
Maeda
Y.
(
1994
)
Precise expression of the cAMP receptor gene, CAR1, during transition from growth to differentiation in Dictyostelium discoideum.
FEBS Lett
342
,
239
241
Araki
T.
,
Abe
T.
,
Williams
J. G.
,
Maeda
Y.
(
1997
)
Symmetry breaking in Dictyostelium morphogenesis: Evidence that a combination of cell cycle stage and positional information dictates cell fate.
Dev. Biol
192
,
645
648
Birnboim
H. C.
(
1983
)
A rapid alkaline extraction method for the isolation of plasmid DNA.
Meth. Enzymol
100
,
243
255
Birnboim
H. C.
,
Doly
J.
(
1979
)
A rapid alkaline extraction procedure for screening recombinant plasmid DNA.
Nucl. Acids Res
7
,
1513
1523
Bonner
J. T.
(
1947
)
Evidence for the formation of cell aggregates by chemotaxis in the development of the cellular slime mold Dictyostelium discoideum.
J. Exp. Zool
106
,
1
26
Bonner
J. T.
,
Barkley
D. S.
,
Hall
E. M.
,
Konijn
T. M.
,
Mason
J. W.
,
O'Keefe
G.
,
Wolfe
P. B.
(
1969
)
Acrasin, acrasinase and the sensitivity to acrasin in Dictyostelium discoideum.
Dev. Biol
20
,
72
87
Chae
S. C.
,
Maeda
Y.
(
1998
)
Preferential expression of the cDNA encoding the proteasome subunit during the growth/differentiation transition of Dictyostelium cells.
Biochem. Biophys. Res. Commun
245
,
231
234
Chae
S. C.
,
Maeda
Y.
(
1998
)
Cloning and sequence analysis of the cDNA encoding the elongation factor-1of Dictyosteliumdiscoideum.
Biochim. Biophys. Acta
1383
,
1
3
Chae
S. C.
,
Inazu
Y.
,
Amagai
A.
,
Maeda
Y.
(
1998
)
Underexpression of a novel gene, dia2, impairs the transition of Dictyostelium cells from growth to differentiation.
Biochem. Biophys. Res. Commun
252
,
278
283
Devreotes
P. N.
(
1994
)
G protein-linked signaling pathways control the developmental program of Dictyostelium.
Neuron
12
,
235
241
Gerisch
G.
(
1961
)
Zellfunktionen und Zellfunktionwechsel in der Entwicklung von Dictyostelium discoideum. V. StadienspezifischeZellkontaktbildung und ihre quantitative Erfassung.
Exp. Cell. Res
25
,
535
554
Howard
P. K.
,
Aher
K. G.
,
Firtel
R. A.
(
1988
)
Establishment of a transient expression system for Dictyosteliumdiscoideum.
Nucl. Acids Res
16
,
2613
2633
Inazu
Y.
,
Chae
S.-C.
,
Maeda
Y.
(
1999
)
Transient expression of a mitochondrial gene cluster including rps4 is essential for the phase-shift of Dictyostelium cells from growth to differentiation.
Dev. Genetics
25
,
339
352
Itoh
M.
,
Noguchi
M.
,
Maeda
Y.
(
1998
)
Overexpression of CAF1 encoding a novel Ca2+-binding protein stimulates the transition of Dictyostelium cells from growth to differentiation.
Dev. Growth Differ
40
,
677
683
Liang
P.
,
Zhu
W.
,
Zhang
X.
,
Guo
Z.
,
O'Connell
R. B.
,
Averboukh
L.
,
Wang
F.
,
Pardee
A. B.
(
1994
)
Differential display using one-base anchored oligo-dT primers.
Nucl. Acids Res
22
,
5763
5764
Louise
D. G.
,
Krishna
K.
,
Sidney
U.
(
1992
)
Phosphatidylinositol glycan (PI-G) anchored membrane proteins.
J. Biol. Chem
267
,
12168
12173
Maeda
Y.
(
1986
)
A new method for inducing synchronous growth of Dictyostelium discoideum cells using temperature shifts.
J. Gen. Microbiol
132
,
1189
1196
Maeda
Y.
,
Ohmori
T.
,
Abe
T.
,
Abe
F.
,
Amagai
A.
(
1989
)
Transition of starving Dictyostelium cells to differentiation phase at a particular position of the cell cycle.
Differentiation
41
,
169
175
Mann
S. K.
,
Firtel
R. A.
(
1978
)
Cyclic AMP regulation of early gene expression in Dictyosteliumdiscoideum: mediation via the cell surface cyclic AMP receptor.
Mol. Cell Biol
7
,
458
469
Michael
T. L.
,
Loomis
W. F.
(
1998
)
A molecular network that produces spontaneous oscillations in excitable cells of Dictyostelium.
Mol. Biol. Cell
9
,
3521
3532
Milne
J. L.
,
Wu
L.
,
Caterina
M. J.
,
Devreotes
P. N.
(
1995
)
Seven helix cAMP receptors stimulate Ca2+entry in the absence of functional G proteins in Dictyostelium.
J. Biol. Chem
270
,
5926
5931
Ohmori
T.
,
Maeda
Y.
(
1987
)
The developmental fate of Dictyostelium discoideum cells depends greatly on the cell-cycle position at the onset of starvation.
Cell Differ
22
,
11
18
Otsuka
H.
,
Van Haastert
P. M.
(
1998
)
A novel Myb homologue initiates Dictyostelium development by induction of adenylyl cyclase expression.
Genes Dev
12
,
1738
1748
Souza
G. M.
,
Lu
S.
,
Kuspa
A.
(
1998
)
YakA, a protein kinase required for the transition from growth to development in Dictyostelium.
Development
125
,
2291
2302
Sun
T. J.
,
Van Haastert
P. J. M.
,
Devreotes
P. N.
(
1990
)
Surface cAMP receptors mediate multiple responses during development in Dictyostelium: Evidenced by antisense mutagenesis.
J. Cell Biol
110
,
1549
1554
Sun
T. J.
,
Devreotes
P. N.
(
1991
)
Gene targeting of the aggregation stage cAMP receptor CAR1 in Dictyostelium.
Genes Dev
5
,
572
582
Watts
D. J.
,
Ashworth
J. M.
(
1970
)
Growth of myxamoebae of the cellular slime mold Dictyostelium discoideum in axenic culture.
Biochem. J
119
,
171
174
Wick
V.
,
Malchow
D.
,
Gerish
G.
(
1978
)
Cyclic AMP stimulated calcium influx into aggregating cells of Dictyostelium discoideum.
Differentiation
59
,
289
297
This content is only available via PDF.