title: ATP-driven tubule extrusion from axonemes without outer dynein arms of sea-urchin sperm flagella.
abstract: We have prepared axonemes without outer dynein arms from sea-urchin (Pseudocentrotus depressus, Hemicentrotus pulcherrimus) sperm flagella by selective solubilization with NaCl. Electron microscopy revealed that the axonemes gradually lost their outer arms in 0.5 M NaCl during 10 min. Such axonemes retained 42.8 +/- 7.3% of their total axonemal ATPase activity and showed C, A, D and B bands in the dynein region of 4% SDS-gel, while a solubilized fraction of the outer arms consisted almost entirely of A band polypeptide. We have succeeded in causing extrusion of the outer doublets from such axonemes by addition of ATP and trypsin. A bundle of outer doublets was sometimes observed to be extruded first from an axoneme and to show bending motion for a while, subsequently followed by a sliding of separate doublets past each other. The speed of the tubule extrusion process was slower and around 60% of that of intact axonemes having both types of arm. These observations indicate that the inner arms have a function equivalent to that of the outer arms, of sliding on adjacent doublets, although the inner arms seem to be constituted from polypeptide(s) different from that of the outer arms.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D004398:Dyneins; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D008854:Microscopy, Electron; D008870:Microtubules / Q000648:ultrastructure*; D012617:Sea Urchins / Q000648:ultrastructure*; D013082:Sperm Tail / Q000187:drug effects / Q000648:ultrastructure*; D013094:Spermatozoa / Q000648:ultrastructure*; D014357:Trypsin
chemical_list: D000255:Adenosine Triphosphate; D014357:Trypsin; D000251:Adenosine Triphosphatases; D004398:Dyneins