Robert A. Bloodgood
School Of Medicine #800732
Charlottesville, VA 22908
Cell-Surface Glycoprotein Dynamics and Cell Locomotion
Current emphasis in this laboratory is being placed on identifying the transmembrane signaling events whereby multivalent ligand crosslinking of flagellar membrane glycoproteins activates the intra-flagellar machinery for redistributing these proteins in the plane of the flagellar membrane. Crosslinking of a population of 350 kDa flagellar membrane glycoproteins results in a calcium influx across the flagellar membrane and a dramatic dephosphorylation of a flagellar membrane-associated phosphoprotein of 60 kDa and pI of 4.8 which binds to the cytoplasmic domain of the 350 kDa glycoprotein. Thecalcium-activated protein phosphatase 2B (calcineurin) appears to mediate the dephosphorylation of the 60 kDa.
Future work will explore the function of the 60 kDa protein in the activation of the flagellar motor machinery responsible for membrane glycoprotein movements. A series of non-gliding mutant cell strains of Chlamydomonas obtained by insertional mutagenesis, are being analyzed in order to shed additional light on the mechanism underlying whole cell locomotion.