Mitotic phosphoepitopes are expressed in Kc cells, neuroblasts and isolated chromosomes of Drosophila melanogaster

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Bousbaa, H (Author) Other; Correia, L (Author) Other; Gorbsky, GJ (Author) Other; Sunkel, CE (Author) ICBAS

Journal

Title: Journal of Cell Science

Vol. 110

Pages: 1979-1988

ISSN: 0021-9533

Publisher: The Company of Biologists Ltd.

Indexing

ISI Web of Knowledge - 19 Citations

Scopus - 19 Citations

Other information

Authenticus ID: P-001-AS4

Abstract (EN): The progression of cells from metaphase to anaphase is thought to be regulated by a checkpoint that delays entry into anaphase until all chromosomes reach a stable hi-polar attachment at the metaphase plate, Previous work has suggested that the 3F3/2 kinetochore phosphoepitopes are involved in this checkpoint system, We show that the 3F3/2 centromere phosphoepitopes are present in Kc cells, third instar larval neuroblasts and isolated chromosomes of Drosophila melanogaster. In tissue culture cells and neuroblasts isolated from third instar larvae, centromere labelling is detected from early prophase to the metaphase-anaphase transition hut absent once cells enter anaphase, During anaphase, the antibody stains the spindle mid zone and during telophase the midbody is labelled until cells separate, In both cell types, the 3F3/2 antibody stains the centrosome from prophase to late telophase, The 3F3/2 staining is retained in Kc cells and third instar larval neuroblasts arrested at the prometaphase state with microtubule inhibitors. Also, two mitotic mutants that show abnormal spindle morphology retain the centromere labelling in a metaphase-like configuration, suggesting that they activate the metaphase-anaphase checkpoint, Finally, mitotic chromosomes isolated in the presence of a phosphatase inhibitor show phosphoepitopes at the primary constriction on the surface of each chromatid, however, chromosomes isolated in the absence of a phosphatase inhibitor do not, Incubation of these chromosomes with ATP causes the rephosphorylation of the phosphoepitopes at the centromere.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10