Mechanism controlling perpendicular alignment of the spindle to the axis of cell division in fission yeast

AUTOR(ES)

Gachet, Yannick

RESUMO

In animal cells, the mitotic spindle is aligned perpendicular to the axis of cell division. This ensures that sister chromatids are separated to opposite sides of the cytokinetic actomyosin ring (CAR). We show that, in fission yeast, spindle rotation is dependent on the interaction of astral microtubules with the cortical actin cytoskeleton. Interaction initially occurs with a region surrounding the nucleus, which we term the astral microtubule interaction zone (AMIZ). Simultaneous contact of astral microtubules from both poles with the AMIZ directs spindle rotation and this requires both actin and two type V myosins, Myo51 and Myo52. Astral microtubules from one pole only then contact the CAR, which is located at the centre of the AMIZ. We demonstrate that the anillin homologue Mid1, which dictates correct placement of the CAR, is necessary to stabilise the mitotic spindle perpendicular to the axis of cell division. Finally, we show that the position of the mitotic spindle is monitored by a checkpoint that regulates the timing of sister chromatid separation.

Documentos Relacionados

• Controlling cell division in yeast and animals: does size matter?
• Promiscuous targeting of Bacillus subtilis cell division protein DivIVA to division sites in Escherichia coli and fission yeast
• Monopolar spindle attachment of sister chromatids is ensured by two distinct mechanisms at the first meiotic division in fission yeast
• Uncontrolled septation in a cell division cycle mutant of the fission yeast Schizosaccharomyces pombe.
• Cohesins Determine the Attachment Manner of Kinetochores to Spindle Microtubules at Meiosis I in Fission Yeast