Wang H, Harrison-Shostak D C, Lemasters J J, Herman B
Department of Cell Biology and Anatomy, School of Medicine, University of North Carolina at Chapel Hill 27599-7090, USA.
Biochem Biophys Res Commun. 1996 Jan 5;218(1):360-4. doi: 10.1006/bbrc.1996.0063.
HCW9 cDNA encodes a rat protein with 95% homology to mouse phospholipase A2 activating protein (PLAP). Its mRNA, which is substantially decreased in rat hepatocytes during chemical hypoxic injury, was found to be expressed in all rat tissues examined, including liver, heart, brain, spleen, lung, skeletal muscle, kidney, and testis. To elucidate the mechanisms responsible for this hypoxia-induced down-regulation of HCW9 mRNA levels, the transcription rate and half-life of HCW9 mRNA were measured. Nuclear run-off assays revealed a 54-57% inhibition in the transcription rate of HCW9 gene during chemical hypoxic injury. The half-life of HCW9 mRNA decreased from approximately 15 min under normoxic conditions to approximately 7 min during chemical hypoxic injury. These findings suggest that HCW9 expression in rat hepatocytes is regulated at both the transcriptional and posttranscriptional levels during chemical hypoxia.
HCW9 cDNA编码一种与小鼠磷脂酶A2激活蛋白（PLAP）具有95%同源性的大鼠蛋白。在化学性低氧损伤期间，其mRNA在大鼠肝细胞中显著减少，但在所有检测的大鼠组织中均有表达，包括肝脏、心脏、大脑、脾脏、肺、骨骼肌、肾脏和睾丸。为了阐明导致这种低氧诱导的HCW9 mRNA水平下调的机制，我们测量了HCW9 mRNA的转录速率和半衰期。核转录分析显示，在化学性低氧损伤期间，HCW9基因的转录速率受到54%-57%的抑制。HCW9 mRNA的半衰期从常氧条件下的约15分钟缩短至化学性低氧损伤期间的约7分钟。这些发现表明，在化学性低氧期间，大鼠肝细胞中HCW9的表达在转录和转录后水平均受到调控。
