Analysis of Dictyostelium TACC reveals differential interactions with CP224 and unusual dynamics of Dictyostelium microtubules.
We have localized TACC to the microtubule-nucleating centrosomal corona and to microtubule plus ends. Using RNAi we proved that Dictyostelium TACC promotes microtubule growth during interphase and mitosis. For the first time we show in vivo that both TACC and XMAP215 family proteins can be differentially localized to microtubule plus ends during interphase and mitosis and that TACC is mainly required for recruitment of an XMAP215-family protein to interphase microtubule plus ends but not for recruitment to centrosomes and kinetochores. Moreover, we have now a marker to study dynamics and behavior of microtubule plus ends in living Dictyostelium cells. In a combination of live cell imaging of microtubule plus ends and fluorescence recovery after photobleaching (FRAP) experiments of GFP-α-tubulin cells we show that Dictyostelium microtubules are dynamic only in the cell periphery, while they remain stable at the centrosome, which also appears to harbor a dynamic pool of tubulin dimers.
Samereier
Matthias
M
Department of Cell Biology, Institute for Biochemistry and Biology, University of Potsdam, Germany.
Baumann
Otto
O
Meyer
Irene
I
Gräf
Ralph
R
D000595:Amino Acid Sequence; D000818:Animals; D018385:Centrosome / Q000378:metabolism; D004023:Dictyostelium / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure*; D036681:Fluorescence Recovery After Photobleaching; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007399:Interphase; D018386:Kinetochores / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure*; D008938:Mitosis; D056004:Molecular Dynamics Simulation; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D017421:Sequence Analysis; D014404:Tubulin / Q000235:genetics / Q000378:metabolism
D008869:Microtubule-Associated Proteins; D015800:Protozoan Proteins; D014404:Tubulin; C411383:centrosomal protein 224-kDa, Dictyostelium; D049452:Green Fluorescent Proteins