Straus D S, Takemoto C D
Biomedical Sciences Division, University of California, Riverside 92521-0121.
Biochim Biophys Acta. 1988 Oct 28;972(1):33-6. doi: 10.1016/0167-4889(88)90099-7.
Deprivation of cultured H4 rat hepatoma cells for an essential amino acid (leucine, methionine, tryptophan or phenylalanine) under conditions in which the cells remain highly viable leads to a decrease in cytoplasmic albumin mRNA. The magnitude of this decrease is greatest in tryptophan-deprived and phenylalanine-deprived cells. In the tryptophan-deprived cells there is approximately a 15-17-fold decrease in albumin mRNA relative to total cytoplasmic RNA, and a 7-8-fold specific decrease in albumin mRNA relative to alpha-tubulin mRNA. Deprivation of the H4 cells for leucine or tryptophan causes approximately a 40-45% decrease in albumin gene transcription; however, this effect does not account for the 15-17-fold decrease in albumin mRNA abundancy caused by tryptophan limitation, or the greater effect of tryptophan limitation as compared to leucine limitation on albumin mRNA. Therefore, the decrease in albumin mRNA caused by tryptophan limitation is caused primarily by a post-transcriptional regulatory mechanism.
在细胞仍保持高活力的条件下，对培养的H4大鼠肝癌细胞剥夺一种必需氨基酸（亮氨酸、蛋氨酸、色氨酸或苯丙氨酸）会导致细胞质白蛋白mRNA减少。这种减少的幅度在色氨酸剥夺和苯丙氨酸剥夺的细胞中最大。在色氨酸剥夺的细胞中，相对于总细胞质RNA，白蛋白mRNA大约减少15 - 17倍，相对于α-微管蛋白mRNA，白蛋白mRNA特异性减少7 - 8倍。对H4细胞剥夺亮氨酸或色氨酸会导致白蛋白基因转录大约减少40 - 45%；然而，这种效应并不能解释色氨酸限制导致的白蛋白mRNA丰度15 - 17倍的减少，也不能解释色氨酸限制与亮氨酸限制相比对白蛋白mRNA的更大影响。因此，色氨酸限制导致的白蛋白mRNA减少主要是由转录后调控机制引起的。
