Tipping of flagellar agglutinins by gametes of Chlamydomonas reinhardtii.
The migration of cross-linked agglutinins to the gametic flagellar tips (tipping) is a hallmark of the Chlamydomonas mating reaction. In this study, an assay was developed to analyze the kinetics and biological requirements for the tipping response: isolated flagella from mt- gametes of C. reinhardtii were allowed to agglutinate to the immotile flagella of pf-18 mt+ gametes, and their migration to the tips was monitored by phase microscopy. The tipping process is shown to require both adhesion and elevated levels of cAMP. The cAMP may activate tipping motors directly. In addition, cAMP stimulates the recruitment of agglutinins to the flagellar surface to replace those inactivated by adhesion. These results are compared with previous studies on the tipping of flagellar surface proteins cross-linked by soluble ligands, and an integrated model is presented.
Goodenough
U W
UW
Department of Biology, Washington University, St. Louis, MO 63130.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000373:Agglutinins / Q000378:metabolism*; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D002448:Cell Adhesion; D002465:Cell Movement / Q000187:drug effects; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000502:physiology*; D003078:Colchicine / Q000494:pharmacology; D004110:Diltiazem / Q000494:pharmacology; D005407:Flagella / Q000187:drug effects / Q000502:physiology*; D005854:Germ Cells / Q000502:physiology*; D007546:Isoquinolines / Q000494:pharmacology; D007811:Lanthanum / Q000494:pharmacology; D008012:Lidocaine / Q000494:pharmacology; D008954:Models, Biological; D010940:Plant Proteins / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*; D012098:Reproduction / Q000187:drug effects; D019311:Staurosporine; D014268:Trifluoperazine / Q000494:pharmacology
D000373:Agglutinins; D000470:Alkaloids; D007546:Isoquinolines; D010940:Plant Proteins; D015800:Protozoan Proteins; D002104:Cadmium; D014268:Trifluoperazine; D003994:Bucladesine; D007811:Lanthanum; C053177:N-(2-(methylamino)ethyl)-5-isoquinolinesulfonamide; D008012:Lidocaine; D004110:Diltiazem; D019311:Staurosporine; D003078:Colchicine; D015056:1-Methyl-3-isobutylxanthine