TY - JOUR
T1 - Protein particles in Chlamydomonas flagella undergo a transport cycle consisting of four phases
AU - Iomini, Carlo
AU - Babaev-Khaimov, Veronica
AU - Sassaroli, Massimo
AU - Piperno, Gianni
PY - 2001/4/2
Y1 - 2001/4/2
N2 - We used an improved procedure to analyze the intraflagellar transport (IFT) of protein particles in Chlamydomonas and found that the frequency of the particles, not only the velocity, changes at each end of the flagella. Thus, particles undergo structural remodeling at both flagellar locations. Therefore, we propose that the IFT consists of a cycle composed of at least four phases: phases II and IV, in which particles undergo anterograde and retrograde transport, respectively, and phases I and III, in which particles are remodeled/ exchanged at the proximal and distal end of the flagellum, respectively. In support of our model, we also identified 13 distinct mutants of flagellar assembly (fla), each defective in one or two consecutive phases of the IFT cycle. The phase I-II mutant fla10-1 revealed that cytoplasmic dynein requires the function of kinesin II to participate in the cycle. Phase I and II mutants accumulate complex A, a particle component, near the basal bodies. In contrast, phase III and IV mutants accumulate complex B, a second particle component, in flagellar bulges. Thus, fla mutations affect the function of each complex at different phases of the cycle.
AB - We used an improved procedure to analyze the intraflagellar transport (IFT) of protein particles in Chlamydomonas and found that the frequency of the particles, not only the velocity, changes at each end of the flagella. Thus, particles undergo structural remodeling at both flagellar locations. Therefore, we propose that the IFT consists of a cycle composed of at least four phases: phases II and IV, in which particles undergo anterograde and retrograde transport, respectively, and phases I and III, in which particles are remodeled/ exchanged at the proximal and distal end of the flagellum, respectively. In support of our model, we also identified 13 distinct mutants of flagellar assembly (fla), each defective in one or two consecutive phases of the IFT cycle. The phase I-II mutant fla10-1 revealed that cytoplasmic dynein requires the function of kinesin II to participate in the cycle. Phase I and II mutants accumulate complex A, a particle component, near the basal bodies. In contrast, phase III and IV mutants accumulate complex B, a second particle component, in flagellar bulges. Thus, fla mutations affect the function of each complex at different phases of the cycle.
KW - Chlamydomonas
KW - Intraflagellar transport
KW - Kinesin II
KW - Temperature-sensitive mutants
KW - Transport cycle
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U2 - 10.1083/jcb.153.1.13
DO - 10.1083/jcb.153.1.13
M3 - Article
C2 - 11285270
AN - SCOPUS:0035795413
SN - 0021-9525
VL - 153
SP - 13
EP - 24
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 1
ER -