title: Drosophila tubulin-binding cofactor B is required for microtubule network formation and for cell polarity.
abstract: Microtubules (MTs) are essential for cell division, shape, intracellular transport, and polarity. MT stability is regulated by many factors, including MT-associated proteins and proteins controlling the amount of free tubulin heterodimers available for polymerization. Tubulin-binding cofactors are potential key regulators of free tubulin concentration, since they are required for α-β-tubulin dimerization in vitro. In this paper, we show that mutation of the Drosophila tubulin-binding cofactor B (dTBCB) affects the levels of both α- and β-tubulins and dramatically destabilizes the MT network in different fly tissues. However, we find that dTBCB is dispensable for the early MT-dependent steps of oogenesis, including cell division, and that dTBCB is not required for mitosis in several tissues. In striking contrast, the absence of dTBCB during later stages of oogenesis causes major defects in cell polarity. We show that dTBCB is required for the polarized localization of the axis-determining mRNAs within the oocyte and for the apico-basal polarity of the surrounding follicle cells. These results establish a developmental function for the dTBCB gene that is essential for viability and MT-dependent cell polarity, but not cell division.
authors.affiliation: Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Alexandre D
authors.initials: AD
authors.lastname: Baffet
authors.forename: Béatrice
authors.initials: B
authors.lastname: Benoit
authors.forename: Jens
authors.initials: J
authors.lastname: Januschke
authors.forename: Jennifer
authors.initials: J
authors.lastname: Audo
authors.forename: Vanessa
authors.initials: V
authors.lastname: Gourhand
authors.forename: Siegfried
authors.initials: S
authors.lastname: Roth
authors.forename: Antoine
authors.initials: A
authors.lastname: Guichet
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D016764:Cell Polarity / Q000235:genetics / Q000502:physiology*; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009154:Mutation; D009865:Oocytes / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D009866:Oogenesis / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D014404:Tubulin / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D008164:Luminescent Proteins; D008869:Microtubule-Associated Proteins; D014404:Tubulin; C578566:tubulin folding cofactor B, Drosophila