| Autor: |
Mami Nomura, Kohei Atsuji, Keiko Hirose, Kogiku Shiba, Ryuji Yanase, Takeshi Nakayama, Ken-ichiro Ishida, Kazuo Inaba |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
Biology Open, Vol 8, Iss 2 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
2046-6390 |
| DOI: |
10.1242/bio.036590 |
| Popis: |
A haptonema is an elongated microtubule-based motile organelle uniquely present in haptophytes. The most notable and rapid movement of a haptonema is ‘coiling’, which occurs within a few milliseconds following mechanical stimulation in an unknown motor-independent mechanism. Here, we analyzed the coiling process in detail by high-speed filming and showed that haptonema coiling was initiated by left-handed twisting of the haptonema, followed by writhing to form a helix from the distal tip. On recovery from a mechanical stimulus, the helix slowly uncoiled from the proximal region. Electron microscopy showed that the seven microtubules in a haptonema were arranged mostly in parallel but that one of the microtubules often wound around the others in the extended state. A microtubule stabilizer, paclitaxel, inhibited coiling and induced right-handed twisting of the haptonema in the absence of Ca2+, suggesting changes in the mechanical properties of microtubules. Addition of Ca2+ resulted in the conversion of haptonematal twist into the planar bends near the proximal region. These results indicate that switching microtubule conformation, possibly with the aid of Ca2+-binding microtubule-associated proteins is responsible for rapid haptonematal coiling. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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