Effects of intracellular ph on the mitotic apparatus and mitotic stage in the sand dollar egg

Watanabe, Kenji; Hamaguchi, Miyako S.; Hamaguchi, Yukihisa

doi:10.1002/(sici)1097-0169(1997)37:3<263::aid-cm8>3.0.co;2-7

Cited by 14 publications

(15 citation statements)

References 31 publications

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“…Although it is unclear how extracellular pH affects in vivo MT stability, a putative mechanism is pH-induced changes in tubulin polymerization. The effects we measured coincide with evidence from other investigators that the quantity and, thus presumably, the stability of MTs polymerized is exquisitely sensitive to pH in vitro (48,49) and in vivo (27). Instead of or in addition to, pH could affect activity of stathmin/Op18, an MT-destabilizer.…”

Section: Discussionsupporting

confidence: 87%

See 1 more Smart Citation

Alteration of the C-terminal Amino Acid of Tubulin Specifically Inhibits Myogenic Differentiation

Chang¹,

Webster²,

Salam³

et al. 2002

Journal of Biological Chemistry

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Section: Discussionsupporting

confidence: 87%

“…Instead, we explored using pH to influence MT stability, based on reports that pH affects MT polymerization in vivo (27). As shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

Alteration of the C-terminal Amino Acid of Tubulin Specifically Inhibits Myogenic Differentiation

Chang¹,

Webster²,

Salam³

et al. 2002

Journal of Biological Chemistry

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“…Spindles in 54 zygotes had no obvious defects in appearance or in length : width ratios, and in most zygotes spindles were properly aligned with the growth axis. These findings are in contrast to those reported for fertilized sand dollar eggs in which lowering pH c from 7.3 to 6.7 by treatment with acetate resulted in elongated spindles with a larger length : width ratio than controls (Watanabe et al 1997).…”

Section: Microtubule Organizationcontrasting

confidence: 99%

Microtubule arrays in fucoid zygotes are sensitive to cytoplasmic pH

Henderson¹,

Kropf²

2001

Phycological Res

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Regulation of microtubule (MT) arrays and embryogenesis by cytoplasmic pH (pH c ) was investigated in zygotes of the brown alga Pelvetia compressa (J. Agardh) De Toni. pH c was clamped to (set to) acidic values using a weak acid, propionic acid (PA), and to alkaline values using a weak base, methylamine (MA). Acidification of pH c from the normal value of 7.4-7.5 to about 7.0 caused disruption of microtubule arrays. The nucleating activity was delocalized from the centrosomes and dispersed over the nuclear envelope, the number of MTs decreased, and MTs failed to extend into the cell cortex. Alkalinization to about pH 8.0 also caused dispersal of nucleating activity, but distinct centrosomes remained. MTs coursed in various directions following MA treatment, giving the array a disorganized appearance. Two MT-dependent processes, rhizoid morphogenesis and cell division, were found to be perturbed by small changes in pH c .

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“…Although intracellular pH is held close to neutral in most cell types, cell signalling involving significant changes in global intracellular pH are well documented [45,46], and these are often exaggerated in cell subdomains [47]. In addition to gelsolin, other actin‐binding proteins such as the ADF/cofilins [48] and EF1α[49] are strongly pH‐dependent so it seems probable that pH transients that occur in cells may act in part through the actin cytoskeleton.…”

Section: A Model For Ph Activationmentioning

confidence: 99%

The activation of gelsolin by low pH

Lagarrigue

Ternent

Maciver

et al. 2003

European Journal of Biochemistry

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Gelsolin is a multidomain and multifunction protein that nucleates the assembly of filaments and severs them. The activation of gelsolin by calcium is a multistep process involving many calcium binding sites that act to unfold the molecule from a tight structure to a more loose form in which three actin‐binding sites become exposed. Low pH is also known to activate gelsolin, in the absence of calcium and this too results in an unfolding of the molecule. Less is known how pH‐activation occurs but we show that there are significant differences in the mechanisms that lead to activation. Crucially, while it is known that the bonds between G2 and G6 are broken by co‐operative occupancy of calcium binding sites in both domains [Lagarrique, E., Maciver, S. K., Fattoum, A., Benyamin, Y. & Roustan, C. (2003) Eur. J. Biochem. 270, 2236–2243.], pH values that activate gelsolin do not result in a weakening of the G2‐G6 bonds. We report the existence of pH‐dependent conformational changes within G2 and in G4–6 that differ from those induced by calcium, and that low pH overrides the requirement for calcium for actin‐binding within G4–6 to a modest extent so that a Kd of 1 µm is measured, compared to 30–40 nm in the presence of calcium. Whereas the pH‐dependent conformational change in G2 is possibly different from the change induced by calcium, the changes measured in G4–6 appear to be similar in both calcium and low pH.

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Effects of intracellular ph on the mitotic apparatus and mitotic stage in the sand dollar egg

Cited by 14 publications

References 31 publications

Alteration of the C-terminal Amino Acid of Tubulin Specifically Inhibits Myogenic Differentiation

Alteration of the C-terminal Amino Acid of Tubulin Specifically Inhibits Myogenic Differentiation

Microtubule arrays in fucoid zygotes are sensitive to cytoplasmic pH

The activation of gelsolin by low pH

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