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The plus‐tip tracking and microtubule stabilizing activities of Javelin‐like regulate microtubule organization and cell polarity
Author(s) -
Baskar Raju,
Bahkrat Anna,
Otani Tetsuhisa,
Wada Housei,
Davidov Geula,
Pandey Himanshu,
Gheber Larisa,
Zarivach Raz,
Hayashi Shigeo,
Abdu Uri
Publication year - 2019
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14944
Subject(s) - microtubule , polarity (international relations) , javelin , tracking (education) , microtubule nucleation , microbiology and biotechnology , biophysics , biology , psychology , cell , centrosome , engineering , aeronautics , genetics , cell cycle , pedagogy , throwing
Cell polarity is essential for building cell asymmetry in all eukaryotic cells. Drosophila oocyte and bristle development require the newly characterized Spn‐F protein complex, which includes Spn‐F, IKK ε, and Javelin‐like (Jvl), to establish polarity. Jvl is a novel microtubule ( MT )‐associated protein; however, the mechanism by which it regulates MT organization is still unknown. We found that overexpression of Jvl stabilizes MT s and that jvl is needed for stable MT arrangement at the bristle tip and organization of the dynamic MT throughout the bristle shaft. At low levels of expression in cultured cells, Jvl behaved as a microtubule plus‐end tracking protein. We demonstrated that Jvl physically interacts with the highly conserved MT end‐binding protein 1 ( EB 1) using yeast two‐hybrid and GST pull‐down assays. This interaction is, however, dispensable for Jvl function in oocyte and bristle development. In addition, using a MT ‐binding assay, we saw that Jvl‐C terminus directly binds to MT s. We also revealed that oocyte developmental arrest caused by Jvl overexpression in the germline can be rescued by mutations in its partners, spn‐F and ikk ε, suggesting that complex formation with Spn‐F and IKK ε is required for Jvl function in vivo . In summary, our results show that the microtubule plus‐end tracking and stabilizing activities of Jvl are central for controlling cell polarity of oocytes and bristles.