Functional insight into the role of Orc6 in septin complex filament formation in Drosophila

Academic Article


  • Septins belong to a family of polymerizing GTP-binding proteins that are important for cytokinesis and other processes that involve spatial organization of the cell cortex. We reconstituted a recombinant Drosophila septin complex and compared activities of the wild-type and several mutant septin complex variants both in vitro and in vivo. We show that Drosophila septin complex functions depend on the intact GTP-binding and/or hydrolysis domains of Pnut, Sep1, and Sep2. The presence of the functional C-terminal domain of sep-tins is required for the integrity of the complex. Drosophila Orc6 protein, the smallest subunit of the origin recognition complex (ORC), directly binds to septin complex and facilitates sep-tin filament formation. Orc6 forms dimers through the interactions of its N-terminal, TFIIB-like domains. This ability of the protein suggests a direct bridging role for Orc6 in stimulating septin polymerization in Drosophila. Studies reported here provide a functional dissection of a Drosophila septin complex and highlight the basic conserved and divergent features among metazoan septin complexes.
  • Published In

    Digital Object Identifier (doi)

    Pubmed Id

  • 9603255
  • Author List

  • Akhmetova K; Balasov M; Huijbregts RPH; Chesnokov I
  • Start Page

  • 15
  • End Page

  • 28
  • Volume

  • 26
  • Issue

  • 1