EFFECT OF VITAMIN-B-6 DEFICIENCY ON THE EXPRESSION OF GLYCOGEN-PHOSPHORYLASE MESSENGER-RNA IN RAT-LIVER AND SKELETAL-MUSCLE

The effect of vitamin B-6 deficiency on the expression of glycogen phosphorylase mRNA in rat liver and skeletal muscle was investigated. The level of phosphorylase mRNA in the muscle of vitamin B-6-deficient rats was reduced to 40% of that in the control rats. By contrast, the phosphorylase mRNA level was increased 5-fold in the liver of the deficient animals. It was also found that the expression of the beta-actin gene, generally regarded as a 'housekeeping' gene, was unaffected by B-6 deficiency in the muscle but was enhanced in the liver of the deficient animals. These observations suggest that vitamin B-6 may modulate the transcriptional activation of the phosphorylase gene in a tissue-specific manner.