Biomaterial Database

Mitotic motors and chromosome segregation: the mechanism of anaphase B. 2011

Ingrid Brust-Mascher, and Jonathan M Scholey

Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA.

Anaphase B spindle elongation plays an important role in chromosome segregation. In the present paper, we discuss our model for anaphase B in Drosophila syncytial embryos, in which spindle elongation depends on an ip (interpolar) MT (microtubule) sliding filament mechanism generated by homotetrameric kinesin-5 motors acting in concert with poleward ipMT flux, which acts as an 'on/off' switch. Specifically, the pre-anaphase B spindle is maintained at a steady-state length by the balance between ipMT sliding and ipMT depolymerization at spindle poles, producing poleward flux. Cyclin B degradation at anaphase B onset triggers: (i) an MT catastrophe gradient causing ipMT plus ends to invade the overlap zone where ipMT sliding forces are generated; and (ii) the inhibition of ipMT minus-end depolymerization so flux is turned 'off', tipping the balance of forces to allow outward ipMT sliding to push apart the spindle poles. We briefly comment on the relationship of this model to anaphase B in other systems.

UI	MeSH Term	Description	Entries
D008870	Microtubules	Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.	Microtubule
D008941	Spindle Apparatus	A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.	Mitotic Apparatus,Mitotic Spindle Apparatus,Spindle Apparatus, Mitotic,Meiotic Spindle,Meiotic Spindle Apparatus,Mitotic Spindle,Apparatus, Meiotic Spindle,Apparatus, Mitotic,Apparatus, Mitotic Spindle,Apparatus, Spindle,Meiotic Spindles,Mitotic Spindles,Spindle Apparatus, Meiotic,Spindle, Meiotic,Spindle, Mitotic,Spindles, Meiotic,Spindles, Mitotic
D004625	Embryo, Nonmammalian	The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.	Embryonic Structures, Nonmammalian,Embryo, Non-Mammalian,Embryonic Structures, Non-Mammalian,Nonmammalian Embryo,Nonmammalian Embryo Structures,Nonmammalian Embryonic Structures,Embryo Structure, Nonmammalian,Embryo Structures, Nonmammalian,Embryo, Non Mammalian,Embryonic Structure, Non-Mammalian,Embryonic Structure, Nonmammalian,Embryonic Structures, Non Mammalian,Embryos, Non-Mammalian,Embryos, Nonmammalian,Non-Mammalian Embryo,Non-Mammalian Embryonic Structure,Non-Mammalian Embryonic Structures,Non-Mammalian Embryos,Nonmammalian Embryo Structure,Nonmammalian Embryonic Structure,Nonmammalian Embryos,Structure, Non-Mammalian Embryonic,Structure, Nonmammalian Embryo,Structure, Nonmammalian Embryonic,Structures, Non-Mammalian Embryonic,Structures, Nonmammalian Embryo,Structures, Nonmammalian Embryonic
D005658	Fungi	A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.	Fungi, Filamentous,Molds,Filamentous Fungi,Filamentous Fungus,Fungus,Fungus, Filamentous,Mold
D000705	Anaphase	The phase of cell nucleus division following METAPHASE, in which the CHROMATIDS separate and migrate to opposite poles of the spindle.	Anaphases
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D016547	Kinesins	A family of microtubule-associated mechanical adenosine triphosphatases, that uses the energy of ATP hydrolysis to move organelles along microtubules including mitosis, meiosis, and axonal transport.	Kinesin,Kinesin Heavy-Chain Protein,Kinesin Light-Chain Protein,Kinesin Light-Chain Proteins,Kinesin Superfamily,Heavy-Chain Protein, Kinesin,Light-Chain Protein, Kinesin,Light-Chain Proteins, Kinesin,Protein, Kinesin Heavy-Chain,Protein, Kinesin Light-Chain,Proteins, Kinesin Light-Chain,Superfamily, Kinesin
D018386	Kinetochores	Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.	Kinetochore
D020090	Chromosome Segregation	The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.	Chromosome Segregations,Segregation, Chromosome,Segregations, Chromosome
D020409	Molecular Motor Proteins	Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).	Motility Proteins,Motor Proteins, Molecular,Proteins, Molecular Motor,Proteins, Motility