Sulphate induces very fast cell rounding and detachment.
Within a few minutes of incubation with SO4(2-), cultured monolayer cells retract into round shapes with drastically reduced surface area. Concomitant elevation of phosphoinositide second messenger levels, viz, 1,2-diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3), is observed. A causal relationship with sulphation seems to be suggested by finding (a) sulphation of an added acceptor, 4-methylumbelliferone, (b) sulphation of endogenous glycosaminoglycan (GAG) polymers, (c) inhibition by phenol sulphotransferase inhibitor, DCNP (2,6-dichloro-4-nitrophenol). DCNP also inhibits the second messenger production and cell rounding. Reduced surface area appears to be caused by massive plasma membrane internalization in a distinctive endocytosis which is also seen in cell rounding from directly imposed ionic gradients. Reducing the surface area would reduce the adhesive or attachment sites. Besides demonstrating a highly efficient cell detachment potential, huge macromolecules appear to be readily internalized. The association of sulphation, signal transduction and cell detachment is novel.
Sit
K H
KH
Department of Anatomy, Faculty of Medicine, National University of Singapore, Kent Ridge.
Wong
K P
KP
D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002477:Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D004705:Endocytosis; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D006923:Hymecromone / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D009596:Nitrophenols / Q000494:pharmacology; D015290:Second Messenger Systems; D013431:Sulfates / Q000378:metabolism / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
C011439:1,2-diacylglycerol; D004075:Diglycerides; D006025:Glycosaminoglycans; D009596:Nitrophenols; D013431:Sulfates; D006923:Hymecromone; C015802:2,6-dichloro-4-nitrophenol; D015544:Inositol 1,4,5-Trisphosphate