Scientific article

TM9/Phg1 and SadA proteins control surface expression and stability of SibA adhesion molecules in Dictyostelium

Published inMolecular biology of the cell, vol. 23, no. 4, p. 679-686
Publication date2012

TM9 proteins form a family of conserved proteins with nine transmembrane domains essential for cellular adhesion in many biological systems, but their exact role in this process remains unknown. In this study, we found that genetic inactivation of the TM9 protein Phg1A dramatically decreases the surface levels of the SibA adhesion molecule in Dictyostelium amoebae. This is due to a decrease in sibA mRNA levels, in SibA protein stability, and in SibA targeting to the cell surface. A similar phenotype was observed in cells devoid of SadA, a protein that does not belong to the TM9 family but also exhibits nine transmembrane domains and is essential for cellular adhesion. A contact site A (csA)-SibA chimeric protein comprising only the transmembrane and cytosolic domains of SibA and the extracellular domain of the Dictyostelium surface protein csA also showed reduced stability and relocalization to endocytic compartments in phg1A knockout cells. These results indicate that TM9 proteins participate in cell adhesion by controlling the levels of adhesion proteins present at the cell surface.

  • Cell Adhesion
  • Cell Adhesion Molecules/genetics/metabolism
  • Cell Membrane/metabolism/ultrastructure
  • Dictyostelium/metabolism/physiology/ultrastructure
  • Endocytosis
  • Membrane Proteins/genetics/metabolism
  • Mutation
  • Protein Stability
  • Protein Transport
  • Protozoan Proteins/metabolism
Research group
Citation (ISO format)
FROQUET, Romain Bruno et al. TM9/Phg1 and SadA proteins control surface expression and stability of SibA adhesion molecules in Dictyostelium. In: Molecular biology of the cell, 2012, vol. 23, n° 4, p. 679–686. doi: 10.1091/mbc.E11-04-0338
Main files (1)
Article (Published version)
ISSN of the journal1059-1524

Technical informations

Creation11/16/2012 6:45:00 PM
First validation11/16/2012 6:45:00 PM
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