S-Adenosylmethionine metabolism in HL-60 cells: effect of cell cycle and differentiation |
| |
| Institution: | 1. University of Texas Health Science Center at Houston, McGovern Medical School, Department of Psychiatry and Behavioral Sciences, Houston, TX 77054, United States;2. Department of Psychiatry & Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States;1. Swiss Federal Institute of Technology Zurich, Department of Biology, Institute of Molecular Health Sciences, Zurich, Otto-Stern Weg 7, 8093 Zurich, Switzerland;2. Life Science Zurich Graduate School, Molecular Life Science Program, University of Zurich, Institute of Molecular Life Sciences, Winterthurerstrasse 190, 8057 Zurich, Switzerland;1. Harvard College, Cambridge, MA 02138, United States of America;2. Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, United States of America;3. MIND Data Science Lab, Cambridge, MA 02139, United States of America;4. MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, United States of America;5. Harvard Medical School, Boston, MA 02115, United States of America |
| |
| Abstract: | The effect of the cell cycle and differentiation on S-adenosylmethionine (SAM) metabolism in HL-60 cells has been investigated. Synthesis and pool sizes of SAM and S-adenosylhomocysteine (SAH) were cell-cycle-independent (SAM, 315, μM; SAH, 4.6 μM). The SAM-synthase (ATP: l-methionine S-adenosyltransferase) of HL-60 cells has a Km for methionine of 12.8±2.0 μM and thus appears to be of the intermediate Km type found in other malignant tissues. The enzyme does not show cell-cycle regulation. Treatment of cells with DMSO resulted in a rapid and marked decrease of SAM and SAH levels without affecting pool turnover or the SAM/SAH ratio. A decrease in SAM concentration could also be observed in a variant cell line resistant to differentiation with DMSO. DMSO inhibited SAM-synthase in cell-free extracts. This inhibition was noncompetitive with respect to l-methionine. Inhibition of SAM-synthase by cycloleucine lowered SAM levels in intact cells, but resulted in differentiation of only a minor percentage of cells. These data indicate that changes in SAM and SAH levels in HL-60 cells seem to be a consequence rather than a cause of differentiation. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
