Milner R J, Brow M D, Cleveland D W, Shinnick T M, Sutcliffe J G
Nucleic Acids Res. 1983 May 25;11(10):3301-15. doi: 10.1093/nar/11.10.3301.
We have determined the 679 nucleotide sequence of a cDNA clone which, by hybridization-translation experiments, corresponds to a 36K chick brain protein. Our studies provide a partial amino acid sequence for this protein, identifying it as chicken glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Antisera raised against purified chicken GAPDH reacted with a 36K protein present in chick brain extracts and estimated to be the fourth most prevalent protein, as determined by either Coomassie Blue staining or by in vitro translation of chick brain mRNA. The amounts of GAPDH mRNA in chick brain, liver and muscle and adult chicken brain are similar, whereas the relative amount of adult chicken muscle GPDH mRNA is greatly elevated and that of adult liver lowered. The GAPDH protein levels showed a similar variation between tissues, suggesting that the levels of GAPDH protein are largely regulated by the amount of available GAPDH mRNA. The chicken GAPDH clone does not hybridize to rat mRNA, even though GAPDH is one of the most evolutionarily conserved proteins, indicating that selection pressures are heavier at the primary protein sequence level than at the nucleic acid sequence level for this gene, a situation contrasting to that of the tubulins.
我们已经确定了一个cDNA克隆的679个核苷酸序列，通过杂交-翻译实验，该序列对应于一种36K的鸡脑蛋白。我们的研究提供了该蛋白的部分氨基酸序列，确定它为鸡甘油醛-3-磷酸脱氢酶（GAPDH）。用纯化的鸡GAPDH制备的抗血清与鸡脑提取物中存在的一种36K蛋白发生反应，通过考马斯亮蓝染色或鸡脑mRNA的体外翻译确定，该蛋白估计是第四种最丰富的蛋白。鸡脑、肝脏、肌肉以及成年鸡脑中GAPDH mRNA的量相似，而成年鸡肌肉中GPDH mRNA的相对量大幅升高，成年肝脏中的则降低。GAPDH蛋白水平在不同组织间呈现类似的变化，这表明GAPDH蛋白水平在很大程度上受可用GAPDH mRNA量的调节。鸡GAPDH克隆与大鼠mRNA不杂交，尽管GAPDH是进化上最保守的蛋白之一，这表明对于该基因，选择压力在一级蛋白质序列水平比在核酸序列水平更大，这种情况与微管蛋白的情况相反。
