Waldegger S, Gabrysch S, Barth P, Fillon S, Lang F
Institut für Physiologie I, Gmelinstr. 5, D-72076 Tübingen, Germany.
Cell Physiol Biochem. 2000;10(4):203-8. doi: 10.1159/000016351.
The human serum and glucocorticoid dependent serine/threonine kinase h-sgk has previously been discovered as cell volume regulated gene. The present study has been performed to elucidate the involvement of p38-kinase in the transcriptional control of h-sgk by osmotic cell shrinkage. The p38-kinase has previously been cloned as the mammalian homologue of HOG1 kinase, which constitutes a part of the osmosensor in the yeast Saccharomyces cerevisiae. Phosphorylated (active) p38-kinase has been estimated with Western blotting, transcription of hsgk using Northern blotting. Both, increase of extracellular NaCl concentration by 50 mmol/l and addition of 10 micromol/l anisomycin increase phosphorylation of the p38-kinase within 5 to 10 minutes. h-sgk transcription is upregulated by addition of 50 mmol/l NaCl and by anisomycin (10 micromol/l), effects completely inhibited by the specific p38-kinase inhibitor, SB 203580 (10 micromol/l). In conclusion, the stimulation of h-sgk transcription by osmotic cell shrinkage is mediated by p38-kinase.
人血清和糖皮质激素依赖性丝氨酸/苏氨酸激酶h-sgk先前已被发现是一种细胞体积调节基因。本研究旨在阐明p38激酶在渗透细胞收缩对h-sgk转录调控中的作用。p38激酶先前已被克隆为HOG1激酶的哺乳动物同源物，HOG1激酶是酿酒酵母渗透压感受器的一部分。通过蛋白质免疫印迹法估计磷酸化（活性）p38激酶，使用Northern印迹法检测hsgk的转录。细胞外NaCl浓度增加50 mmol/l以及添加10 μmol/l茴香霉素均可在5至10分钟内增加p38激酶的磷酸化。添加50 mmol/l NaCl和茴香霉素（10 μmol/l）可上调h-sgk转录，而特异性p38激酶抑制剂SB 203580（10 μmol/l）可完全抑制这些作用。总之，渗透细胞收缩对h-sgk转录的刺激是由p38激酶介导的。
