RRC ID 28939
Author Harloff C, Gerisch G, Noegel AA.
Title Selective elimination of the contact site A protein of Dictyostelium discoideum by gene disruption.
Journal Genes Dev
Abstract The contact site A glycoprotein is a developmentally regulated cell-surface component expressed during the aggregation stage of Dictyostelium discoideum. This protein has been implicated in the EDTA-stable (Ca2(+)-independent) type of cell adhesion of aggregating cells. The gene coding for the contact site A protein was disrupted by homologous recombination, using a transformation vector that contained a 1.0-kb cDNA fragment as an insert. Transformants that did not express the protein were identified by colony immunoblotting. These transformants produced three truncated contact site A transcripts. One of them was controlled by the original contact site A promoter, as indicated by its strict developmental regulation and cAMP inducibility; the other two transcripts were transcribed from the actin 6 promoter of the vector. When cell adhesion was assayed in the transformants by agitating suspended cells in an agglutinometer, EDTA-stable adhesion was drastically reduced as compared to wild type, confirming that the contact site A glycoprotein acts as a cell-adhesion molecule. However, aggregation of the transformed cells on an agar surface was not remarkably altered. These results suggest that the contact site A glycoprotein is responsible for a 'fast' type of cell adhesion that is essential when aggregating cells are subjected to shear. When cells are not mechanically disturbed, a 'slow' type of adhesion mediated by other molecules is sufficient for their aggregation.
Volume 3(12A)
Pages 2011-9
Published 1989-12-1
DOI 10.1101/gad.3.12a.2011
PMID 2515990
MeSH Blotting, Northern Blotting, Southern Cell Adhesion Cell Adhesion Molecules / metabolism* Dictyostelium / genetics* Dictyostelium / physiology Edetic Acid / pharmacology Fungal Proteins / genetics Fungal Proteins / metabolism* Genes, Fungal* Glycoproteins / genetics Glycoproteins / metabolism* Immunoblotting Protozoan Proteins* Restriction Mapping Transcription, Genetic Transformation, Genetic
IF 9.527
Times Cited 77
Cellular slime molds S00254