@article{mbs:/content/journal/micro/10.1099/mic.0.000403, author = "Kimura, Yoshio and Tanaka, Chihiro and Sasaki, Katsuho and Sasaki, Masashi", title = "High concentrations of intracellular Ap4A and/or Ap5A in developing Myxococcus xanthus cells inhibit sporulation", journal= "Microbiology", year = "2017", volume = "163", number = "1", pages = "86-93", doi = "https://doi.org/10.1099/mic.0.000403", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.000403", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "diadenosine pentaphosphate", keywords = "ApnA hydrolase", keywords = "Myxococcus xanthus", keywords = "diadenosine tetraphosphate", abstract = "Diadenosine polyphosphates (Ap n A) are thought to act as signalling molecules regulating stress responses and biofilm formation in prokaryotes. However, Ap n A function in Myxococcus xanthus remains unknown. Here, we investigated the role of Ap n A in M. xanthus, using the wild-type and Ap n A hydrolase (apaH) mutant strains exposed to various stress conditions. In both wild-type and apaH mutant cells cultured on starvation medium (CF agar), the levels of intracellular diadenosine tetraphosphate (Ap4A) and pentaphosphate (Ap5A) increased several fold during the first 16 h of development and decreased gradually thereafter. The levels of Ap4A and Ap5A in the apaH mutant were about 5- and 11-fold higher than those in the wild-type strain at 16 h, respectively. Ap n A hydrolase activity of the wild-type strain increased 1.5-fold during the first 8 h of development, and it then gradually decreased. The apaH mutant formed spores 1–2 days after the wild-type strain did, and the yield of viable spores was 5.5 % of that in the wild-type strain 5 days after inoculation onto CF agar. These results suggest the possibility that high intracellular levels of Ap4A and/or Ap5A may inhibit M. xanthus sporulation at the early stage of development and that the bacteria reduce intracellular Ap4A and Ap5A accumulation through Ap n A hydrolase activity.", }