Schmidt, A and Windisch, C and Holler, E (1996) Nuclear accumulation and homeostasis of the unusual polymer beta-poly(L-malate) in plasmodia of Physarum polycephalum. EUROPEAN JOURNAL OF CELL BIOLOGY, 70 (4). pp. 373-380. ISSN 0171-9335,
Full text not available from this repository.Abstract
The plasmodium of Physarum polycephalum specifically contains an unusual polyester, beta-poly(L-malate), which is not found in any of the mononucleate forms of its life cycle. Plasmodia growing on D-glucose have been analyzed for beta-poly(L-malate) in nuclei, cytosol and culture medium after cell fractionation, purification by chromatography on DEAE-cellulose and digestion of proteins/nucleic acids. Nuclei contained 400 pg polymer per 1 g of plasmodia, corresponding to a nuclear concentration of 230 mM L-malyl residues, not depending on growth rates, lengths of growth periods, and the growth form as micro- or macroplasmodia. The synthetic rate increased during the phase of rapid enlargement of the nuclei after mitosis. beta-Poly(L-malate) was polydisperse in molecular mass, these tending to be higher in nuclear than in cytosolic extracts and being lowest in the culture medium. beta-Poly(L-malate) was not degraded, when contained in plasmodia, in contrast to degradation and the occurrence of low molecular mass polymer in the culture medium. During pulse-chase feeding with D-[C-14]glucose (0.8 mu mCi/mol), beta-[C-14]poly(L-malate) appearance followed kinetics indicating a release of polymer from nuclei into the culture medium when it was in excess of a threshold. Injection experiments with purified beta-[C-14]poly(L-malate) revealed a re-entry from the cytoplasm into the nuclei and thus the possibility of commutation between the cytoplasm and the nuclei. The observed homeostasis in nuclei supports the assumption that beta-poly(L-malate) plays an essential role in growing plasmodia.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | L-MALATE; ALPHA; plasmodium; Physarum polycephalum; beta-poly(L-malate); nuclear division; synchrony |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:35 |
| URI: | https://pred.uni-regensburg.de/id/eprint/51561 |
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