Transcription of thrombomodulin mRNA in mouse hemangioma cells is increased by cycloheximide and thrombin.
AUTOR(ES)
Dittman, W A
RESUMO
We have measured mRNA levels for thrombomodulin, an endothelial membrane cofactor for the activation of protein C by thrombin, in a mouse hemangioma cell line. Cycloheximide, an inhibitor of protein synthesis, increased levels of thrombomodulin mRNA, as measured in an S1 nuclease protection assay, to 2.5-4.0 times control levels. Thrombomodulin transcription in response to cycloheximide treatment, as determined by nuclear run-on analysis, was 3.9 +/- 1.3 (mean +/- SD) times that found in untreated cells. Thrombin also increased thrombomodulin mRNA levels to 151 +/- 21% (mean +/- SD) of control levels after 2 hr. Transcription increased in response to thrombin by 2.1- to 7.3-fold. The combination of thrombin and cycloheximide had no additive effect on thrombomodulin mRNA levels. Thrombin treatment of hemangioma cells also caused an increase in thrombomodulin protein synthesis to 142 +/- 17% (mean +/- SD) of control levels as determined by immunoprecipitation of [32S]methionine-labeled thrombomodulin. We conclude that thrombomodulin expression is determined in part by the rate of transcription and that thrombomodulin mRNA levels in hemangioma cells are increased by treatment with cycloheximide or thrombin. The increased transcription in response to cycloheximide suggests the existence of a labile protein repressor of thrombomodulin transcription.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=298019Documentos Relacionados
- Human thrombomodulin is not an efficient inhibitor of the procoagulant activity of thrombin.
- Expression of the c-myb and c-myc genes is regulated independently in differentiating mouse erythroleukemia cells by common processes of premature transcription arrest and increased mRNA turnover.
- Splicing of mRNA mediated by tRNA sequences in mouse cells
- Replication of Measles Virus: Continued Synthesis of Nucleocapsid RNA and Increased Synthesis of mRNA in the Presence of Cycloheximide
- Single amino acid substitutions dissociate fibrinogen-clotting and thrombomodulin-binding activities of human thrombin.