Specific cooperation between imp-α2 and imp-β/ketel in spindle assembly during drosophila early nuclear divisions

Erika Virágh, Mátyás Gorjánácz, István Török, Tolga Eichhorn, Sowjanya Kallakuri, Tamás Szlanka, I. Kiss, Bernard M. Mechler

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The multifunctional factors Imp-α and Imp-β are involved in nuclear protein import, mitotic spindle dynamics, and nuclear membrane formation. Further more, each of the three members of the Imp-α family exerts distinct tasks during development. In Drosophila melanogaster, the imp-α2gene is critical during oogenesis for ring canal assembly; specific mutations, which allow oogenesis to proceed normally,were found to block early embryonic mitosis. Here, we show that imp-α2 and imp-β genetically interact during early embryonic development, and we characterize the pattern of defects affecting mitosis in embryos laid by heterozygous imp-α2D14 and impβKetRE34 females. Embryonic development is arrested in these embryos but is unaffected in combinations between imp-βKetRE34 and null mutations in imp-α1 or imp-α3. Furthermore, the imp-α2D14/imp-βKetRE34 interaction could only be rescued by an imp-α2 transgene, albeit not imp-α1 or imp-α3, showing the exclusive imp-α2 function with imp-β.Use of transgenes carrying modifications in the major Imp-α2domains showed the critical requirement of the nuclear localization signal binding (NLSB) site in this process. In the mutant embryos,we found metaphase-arrested mitoses made of enlarged spindles, suggesting an unrestrained activity of factors promoting spindle assembly. In accordance with this, we found that Imp-βKetRE34 and Imp-βKetD bind a high level of RanGTP/GDP, and a deletion decreasing RanGTP level suppresses the imp-βKetRE34 phenotype. These data suggest that a fine balance among Imp-α2, Imp-β,RanGTP, and theNLS cargos is critical for mitoticprogression during early embryonic development.

Original languageEnglish
Pages (from-to)1-14
Number of pages14
JournalG3: Genes, Genomes, Genetics
Volume2
Issue number1
DOIs
Publication statusPublished - Jan 2012

Fingerprint

Cell Nucleus Division
Mitosis
Drosophila
Embryonic Development
Oogenesis
Embryonic Structures
Transgenes
Nuclear Localization Signals
Mutation
Spindle Apparatus
Cell Nucleus Active Transport
Nuclear Envelope
Metaphase
Nuclear Proteins
Drosophila melanogaster
Binding Sites
Phenotype

Keywords

  • Drosophila
  • Genetic interaction
  • Importins
  • Mitosis
  • Spindle formation

ASJC Scopus subject areas

  • Genetics
  • Molecular Biology
  • Genetics(clinical)

Cite this

Virágh, E., Gorjánácz, M., Török, I., Eichhorn, T., Kallakuri, S., Szlanka, T., ... Mechler, B. M. (2012). Specific cooperation between imp-α2 and imp-β/ketel in spindle assembly during drosophila early nuclear divisions. G3: Genes, Genomes, Genetics, 2(1), 1-14. https://doi.org/10.1534/g3.111.001073

Specific cooperation between imp-α2 and imp-β/ketel in spindle assembly during drosophila early nuclear divisions. / Virágh, Erika; Gorjánácz, Mátyás; Török, István; Eichhorn, Tolga; Kallakuri, Sowjanya; Szlanka, Tamás; Kiss, I.; Mechler, Bernard M.

In: G3: Genes, Genomes, Genetics, Vol. 2, No. 1, 01.2012, p. 1-14.

Research output: Contribution to journalArticle

Virágh, E, Gorjánácz, M, Török, I, Eichhorn, T, Kallakuri, S, Szlanka, T, Kiss, I & Mechler, BM 2012, 'Specific cooperation between imp-α2 and imp-β/ketel in spindle assembly during drosophila early nuclear divisions', G3: Genes, Genomes, Genetics, vol. 2, no. 1, pp. 1-14. https://doi.org/10.1534/g3.111.001073
Virágh, Erika ; Gorjánácz, Mátyás ; Török, István ; Eichhorn, Tolga ; Kallakuri, Sowjanya ; Szlanka, Tamás ; Kiss, I. ; Mechler, Bernard M. / Specific cooperation between imp-α2 and imp-β/ketel in spindle assembly during drosophila early nuclear divisions. In: G3: Genes, Genomes, Genetics. 2012 ; Vol. 2, No. 1. pp. 1-14.
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