Involvements of a novel protein, DIA2, in cAMP signaling and spore differentiation during Dictyostelium development.
The novel gene dia2 (differentiation-associated gene 2) was originally isolated as a gene expressed specifically in response to initial differentiation of Dictyostelium discoideum Ax-2 cells. Using dia2(AS) cells in which the dia2 expression was inactivated by the antisense RNA method, DIA2 protein was found to be required for cAMP signaling during cell aggregation. During late development, the DIA2 protein changed its location from the endoplasmic reticulum (ER) to prespore-specific vacuoles (PSVs) that are specifically present in prespore cells of the slug. In differentiating prestalk cells, however, DIA2 was found to be nearly lost from the cells. Importantly, exocytosis of PSVs from prespore cells and the subsequent spore differentiation were almost completely impaired in dia2(AS) cells. In addition, spore induction by externally applied 8-bromo cAMP was significantly suppressed in dia2(AS) cells. Taken together, these results strongly suggested that DIA2 might be closely involved in cAMP signaling and spore differentiation as well as in the initiation of differentiation during Dictyostelium development.
Hirata
Kaori
K
Department of Developmental Biology and Neurosciences Graduate School of Life Sciences Tohoku University Aoba, Sendai 980-8578, Japan.
Amagai
Aiko
A
Chae
Soo-Cheon
SC
Hirose
Shigenori
S
Maeda
Yasuo
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D000242:Cyclic AMP / Q000378:metabolism*; D017931:DNA Primers; D004023:Dictyostelium / Q000254:growth & development* / Q000502:physiology; D005089:Exocytosis; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction; D013172:Spores, Fungal