A new collection of thermosensitive endocytosis mutants in the cellular slime mold Dictyostelium discoideum

Abstract

We used a photoactivatable fluid-phase marker to isolate a new collection of thermosensitive endocytosis mutants in the cellular slime mold Dictyostelium discoideum. All the strains were thermosensitive for growth on bacteria or axenic medium at 27°C. Initial rates endocytosis rapidly decreased upon incubation at the restrictive temperature, but surprisingly most of the strains showed a transient recovery of activity with prolonged exposure 27°C. Endocytosis and exocytosis activities were uncoupled for some of the cell lines at 27°C whereas the others had to be shifted to 29°C. Further molecular analysis of these mutants could lead to the discovery of new proteins involved in endocytosis and its regulation.