Heat stress induces a glycosylation of membrane sterol in myxoamoebae of a true slime mold, Physarum polycephalum.
To know the very early events occurring after heat shock, the changes of membrane lipids were examined. Heat stress induced the production of a certain glycolipid in the myxoamoebae of Physarum polycephalum in a few minutes. The purified glycolipid was determined to be a poriferasterol monoglucoside by structural studies that was previously reported to be expressed during the differentiation of Physarum cells from haploid myxoamoebae to diploid plasmodia (Murakami-Murofushi, K., Nakamura, K., Ohta, J., Suzuki, M., Suzuki, A., Murofushi, H., and Yokota, T. (1987) J. Biol. Chem. 262, 16719-16723). The activity of UDP-glucose:poriferasterol glucosyltransferase (Murakami-Murofushi, K., and Ohta, J. (1989) Biochim. Biophys. Acta 992, 412-415) was also expressed rapidly after heat shock. Thus, the activation of sterol glucosyltransferase and the production of sterol-glucoside were considered to be important events that were involved in the signal transduction system to induce some succeeding heat-shock responses, such as the synthesis of heat-shock proteins.
Murakami-Murofushi
K
K
Department of Biology, Faculty of Science, Ochanomizu University, Tokyo, Japan.
Nishikawa
K
K
Hirakawa
E
E
Murofushi
H
H
D000818:Animals; D005964:Glucosyltransferases / Q000378:metabolism; D006017:Glycolipids / Q000378:metabolism*; D006031:Glycosylation; D018882:Heat Stress Disorders; D013058:Mass Spectrometry; D008563:Membrane Lipids / Q000378:metabolism*; D016839:Physarum polycephalum / Q000378:metabolism*; D015398:Signal Transduction; D013261:Sterols / Q000378:metabolism*
D006017:Glycolipids; D008563:Membrane Lipids; D013261:Sterols; D005964:Glucosyltransferases