Choudhury M, Bag J
Department of Molecular Biology and Genetics, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Nucleic Acids Res. 1998 Oct 15;26(20):4765-70. doi: 10.1093/nar/26.20.4765.
The expression of genes for contractile proteins during myogenesis is coordinately regulated. Uncoupling the expression of the slow/cardiac troponin C (sTnC) gene from this process with an antisense phosphorothioate oligodeoxynucleotide (ODN) was used to examine the presence of any post-transcriptional mechanisms for regulating muscle protein synthesis. Approximately 70 and 50% decreases in sTnC polypeptide synthesis and mRNA levels, respectively, were achieved after 4 days antisense treatment. This decrease in sTnC polypeptide synthesis was not reflected in a similar decline in the steady-state level of this polypeptide. Extension of the ODN treatment to 7 days was required to produce a substantial decrease in the steady-state level of sTnC polypeptide. Our investigation suggests that during the 4-day treatment, the affected cells stabilized the sTnC polypeptide level by increasing its half-life. However, the stabilizing effect appears to be overridden during prolonged (7 days) antisense ODN treatment. Measurement of the polypeptide synthesis and mRNA levels of several contractile proteins showed no evidence of cross-regulation among the genes to coordinately regulate their expression levels.
在肌生成过程中，收缩蛋白基因的表达受到协同调节。利用反义硫代磷酸酯寡脱氧核苷酸（ODN）使慢肌/心肌肌钙蛋白C（sTnC）基因的表达与该过程解偶联，以检测调节肌肉蛋白合成的任何转录后机制的存在。反义处理4天后，sTnC多肽合成和mRNA水平分别下降了约70%和50%。sTnC多肽合成的这种下降并未反映在该多肽稳态水平的类似下降中。需要将ODN处理延长至7天，才能使sTnC多肽的稳态水平大幅下降。我们的研究表明，在4天的处理过程中，受影响的细胞通过增加其半衰期来稳定sTnC多肽水平。然而，在延长（7天）的反义ODN处理过程中，这种稳定作用似乎被克服了。对几种收缩蛋白的多肽合成和mRNA水平的测量表明，基因之间没有交叉调节的证据来协同调节它们的表达水平。
