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Mast, a conserved microtubule‐associated protein required for bipolar mitotic spindle organization
Author(s) -
Lemos Catarina L.,
Sampaio Paula,
Maiato Helder,
Costa Madalena,
Omel'yanchuk Leonid V.,
Liberal Vasco,
Sunkel Claudio E.
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.14.3668
Subject(s) - biology , microtubule , microbiology and biotechnology , mitosis , spindle apparatus , mast (botany) , spindle pole body , mast cell , genetics , cell division , cell , immunology
Through mutational analysis in Drosophila , we have identified the gene multiple asters ( mast ), which encodes a new 165 kDa protein. mast mutant neuroblasts are highly polyploid and show severe mitotic abnormalities including the formation of mono‐ and multi‐polar spindles organized by an irregular number of microtubule‐organizing centres of abnormal size and shape. The mast gene product is evolutionarily conserved since homologues were identified from yeast to man, revealing a novel protein family. Antibodies against Mast and analysis of tissue culture cells expressing an enhanced green fluorescent protein–Mast fusion protein show that during mitosis, this protein localizes to centrosomes, the mitotic spindle, centromeres and spindle midzone. Microtubule‐binding assays indicate that Mast is a microtubule‐associated protein displaying strong affinity for polymerized microtubules. The defects observed in the mutant alleles and the intracellular localization of the protein suggest that Mast plays an essential role in centrosome separation and organization of the bipolar mitotic spindle.