A density-sensing factor controls development in Dictyostelium.
For an unknown reason, several genes expressed during Dictyostelium development are regulated by cell density. This is mediated by an 80-kD glycoprotein, conditioned medium factor (CMF), which is slowly secreted and simultaneously sensed by starved cells. To examine further this eukaryotic cell density-sensing mechanism, we have isolated a cDNA encoding CMF. The derived amino acid sequence of CMF shows no obvious similarity to any known protein and thus may represent a new class of eukaryotic intercellular signal. CMF antisense transformants do not aggregate, whereas normal development is restored by the addition of purified CMF protein. This suggests that CMF might synchronize the onset of development in Dictyostelium by triggering aggregation when a majority of the cells in a given area have starved, as signaled by CMF secretion.
Jain
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Howard Hughes Medical Institute, Rice University, Houston, Texas 77251-1892.
Yuen
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Taphouse
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Gomer
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RH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015815:Cell Adhesion Molecules / Q000235:genetics*; D002449:Cell Aggregation / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics; D004023:Dictyostelium / Q000235:genetics / Q000254:growth & development*; D005800:Genes, Fungal; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D015800:Protozoan Proteins; D012331:RNA, Fungal / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D014170:Transformation, Genetic
D015815:Cell Adhesion Molecules; D004271:DNA, Fungal; D006023:Glycoproteins; D015800:Protozoan Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; C052291:cell cohesion molecule, Dictyostelium