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Inositolless death and the lack of progression through the mitotic cell cycle to anaphase in S. cerevisiae (801.4)

2014; Wiley; Volume: 28; Issue: S1 Linguagem: Inglês

10.1096/fasebj.28.1_supplement.801.4

1530-6860

Barbara A. Hanson, Paul O’Connor, John Frandina, Joseph Pittari, Jean Munezero, Vincent Croglio,

Microtubule and mitosis dynamics

When an inositol mutant ( MC6A ) of S. cerevisiae is starved for inositol, the cells undergo cellular changes that result in the loss of viability known as inositolless death. One target of inositolless death in S. cerevisiae may be the mitotic cell cycle because of the accumulation of polymerized tubulin in these cells. Normally, tubulin starts to depolymerize during anaphase of the cell cycle. One explanation for polymerized tubulin is that the cells enter the cell cycle but do not progress through anaphase where this would occur. To answer this question the levels of mRNA for the genes: Securin ( Pds1 ), Separin ( Esp1 ) and a major subunit ( Apc1 ) of the anaphase‐promoting complex, were measured using RT‐PCR with RNA extracted from cells grown in the presence and absence of inositol for 0, 3, and 24 h. The mRNA levels for Pds1 and Apc1 declined to 57% and 55% of control levels at 3 h and 27% and 33% at 24h. The mRNA levels for Esp1 declined the most rapidly to 22% of control levels at 3h and to 20% at 24h (Fig. 5). The rapid reduction in Esp1 mRNAs and the resulting low levels of the Esp1p protease may prevent the separation of sister chromatids. This would prevent the start of anaphase and the resulting spindle microtubule depolymerization. Grant Funding Source : Canisius College