Chondramides, novel cyclodepsipeptides from myxobacteria, influence cell development and induce actin filament polymerization in the green alga Micrasterias.

The effects of chondramides A-D, new actin targeting cyclodepsipeptides from the myxobacterium Chondromyces crocatus, are probed on the unicellular green alga Micrasterias denticulata, a model organism for studies on cytomorphogenesis. All four chondramides readily enter the cells and cause severe shape malformations when applied during growth. However, the four derivatives have different lowest effective concentrations. Chondramide A: 20 microM, chondramide B: 15 microM, chondramide C: 5 microM chondramide D: 10 microM. At the ultrastructural level, chondramide C, the most effective drug, causes the appearance of abnormal, dense F-actin bundles, and a substantial increase in ER, which covers large parts of the developing semicell. Also the secondary cell wall is malformed by the drug. When chondramide C effects are investigated by means of indirect immunofluorescence, alterations of the F-actin system are also visible. Instead of the cortical F-actin network of untreated controls, distinct parts of the cell are covered by abundant F-actin aggregations. Phalloidin staining of chondramide C treated cells results in a decreased fluorescence in a time-dependent manner due to binding competitions between these drugs. F-actin polymerizing and bundling capacities of chondramides A-D are presented in Micrasterias for the first time, and may in future make this substances a useful tool for cell biological research.

Holzinger A ，Lütz-Meindl U 《cell motility and the cytoskeleton》

Jasplakinolide, a novel actin targeting peptide, inhibits cell growth and induces actin filament polymerization in the green alga Micrasterias.

Holzinger A ，Meindl U 《cell motility and the cytoskeleton》

The chondramides: cytostatic agents from myxobacteria acting on the actin cytoskeleton.

Sasse F ，Kunze B ，Gronewold TM ，Reichenbach H ... -  《JNCI-Journal of the National Cancer Institute》

Chondramides A approximately D, new antifungal and cytostatic depsipeptides from Chondromyces crocatus (myxobacteria). Production, physico-chemical and biological properties.

Kunze B ，Jansen R ，Sasse F ，Höfle G ，Reichenbach H ... -  《JOURNAL OF ANTIBIOTICS》

Polarity establishment requires dynamic actin in fucoid zygotes.

Hable WE ，Miller NR ，Kropf DL 《PROTOPLASMA》