Dgp71WD is required for the assembly of the acentrosomal meiosis I spindle, and is not a general targeting factor for the γ-TuRC

R Reschen, Nathalie Colombie, J Wheatley, J Dobbelaere, D St Johnston, Hiroyuki Ohkura, J Raff

Research output: Contribution to journalArticlepeer-review

Abstract

Dgp71WD/Nedd1 proteins are essential for mitotic spindle formation. In human cells, Nedd1 targets γ-tubulin to both centrosomes and spindles, but in other organisms the function of Dgp71WD/Nedd1 is less clear. In Drosophila cells, Dgp71WD plays a major part in targeting γ-tubulin to spindles, but not centrosomes, while in Xenopus egg extracts, Nedd1 acts as a more general microtubule (MT) organiser that can function independently of γ-tubulin. The interpretation of these studies, however, is complicated by the fact that some residual Dgp71WD/Nedd1 is likely present in the cells/extracts analysed. Here we generate a Dgp71WD null mutant lacking all but the last 12 nucleotides of coding sequence. The complete loss of Dgp71WD has no quantifiable effect on γ-tubulin or Centrosomin recruitment to the centrosome in larval brain cells. The recruitment of γ-tubulin to spindle MTs, however, is severely impaired, and spindle MT density is reduced in a manner that is indistinguishable from cells lacking Augmin or γ-TuRC function. In contrast, the absence of Dgp71WD leads to defects in the assembly of the acentrosomal female Meiosis I spindle that are more severe than those seen in Augmin or γ-TuRC mutants, indicating that Dgp71WD has additional functions that are independent of these complexes in oocytes. Moreover, the localisation of bicoid RNA during oogenesis, which requires γ-TuRC function, is unperturbed in Dgp71WD120 mutants. Thus, Dgp71WD is not simply a general cofactor required for γ-TuRC and/or Augmin targeting, and it appears to have a crucial role independent of these complexes in the acentrosomal Meiosis I spindle.
Original languageEnglish
Pages (from-to)422-429
JournalBiology Open
Volume1
Issue number5
DOIs
Publication statusPublished - 2012

Keywords / Materials (for Non-textual outputs)

  • Dgp71WD
  • Centrosome
  • Mitosis
  • Meiosis

Fingerprint

Dive into the research topics of 'Dgp71WD is required for the assembly of the acentrosomal meiosis I spindle, and is not a general targeting factor for the γ-TuRC'. Together they form a unique fingerprint.

Cite this