A new cyclitol derivative influences inositol metabolism in Neurospora crassa.

Cyclitol derivatives have been synthesized and screened for growth inhibitory effect upon prokaryotic and eukaryotic organisms. One derivative, (2S,3R,5R)-3-azido-2-benzoyloxy-5-hydroxycyclohexanone, was studied in detail: it has no effect upon bacteria, but it is inhibitory to Neurospora crassa. In Neurospora crassa it increased the amount of myo-inositol-1-phosphate synthase and inhibited the activity of myo-inositol-monophosphatase.

Inositol derivatives down-regulate c-myc inducing growth arrest without differentiation.

Cyclitol derivatives that are structurally related to myo-inositol induce growth arrest without differentiation in human promyelocytic leukemia (HL60) cells. An early effect is the rapid down-regulation of c-myc mRNA levels. This was observed also in several mouse and human lines carrying either normal or rearranged myc.

Characterization of a mutation that causes overproduction of inositol in Neurospora crassa.

Slow-growing (inl+/-) spontaneous mutants have been isolated from an inositol requiring (inl) strain of Neurospora crassa that produces defective myo-inositol-1-phosphate synthase (MIPS), the enzyme responsible for the production of inositol-1-phosphate from glucose-6-phosphate. The defective enzyme has some residual activity. In the inl+/- strain the synthesis of the defective enzyme is enhanced, which enables the strain to grow slowly on minimal medium.

Defective myo-inositol-1-phosphate synthase production in an inositolless double mutant Neurospora crassa strain.

A slow growing inl+/- mutant was isolated from an inositol dependent (inl) Neurospora crassa strain. The latter strain produces defective myo-inositol-1-phosphate synthase which has residual activity. Inositol, similarly to that found in wild and inl mutant strains, represses the enzyme production in the inl+/- strain as well.

Isolation and characterization of a DNA-uptake-stimulating protein from the culture medium of Neurospora crassa slime strain.

A protein fraction was purified to homogeneity from the culture medium of the wall-less (slime) strain of Neurospora crassa (FGSC 1118), which proved to be identical with DNA-uptake-stimulating factor (designated DUSF), which has been described earlier [Schablik, M. and Szabó, G. (1981) FEMS Microbiol.