Autelli R, Persson L, Baccino F M
Dipartimento di Medicina ed Oncologia Sperimentale, Università di Torino, Italy.
Biochem J. 1995 Nov 15;312 ( Pt 1)(Pt 1):13-6. doi: 10.1042/bj3120013.
In HMOA cells [Mamont, Duchesne, Grove and Tardif (1978) Exp. Cell Res. 115, 387-393] the half-life of ornithine decarboxylase (ODC) is 8-14 h instead of 15 min as in the Hepatoma Tissue Culture parental cells, due to a single amino acid substitution [Miyazaki, Matsufuji, Murakami and Hayashi (1993) Eur. J. Biochem. 214, 837-844]. We demonstrate for the first time that HMOA cells possess two forms of ODC mRNA that are translated into two proteins differing greatly in turnover rates. We have cloned and transfected the cDNAs for the two ODC forms into COS-1 cells for a direct measurement of their turnover rate. The variant ODC form was much more stable than the wild-type protein, with a half-life of 14 h as compared with 2.5 h.
在HMOA细胞中[马蒙、杜谢内、格罗夫和塔尔迪夫（1978年），《实验细胞研究》第115卷，第387 - 393页]，鸟氨酸脱羧酶（ODC）的半衰期为8 - 14小时，而不像肝癌组织培养亲本细胞那样为15分钟，这是由于单个氨基酸替换造成的[宫崎、松藤、村上和林（1993年），《欧洲生物化学杂志》第214卷，第837 - 844页]。我们首次证明HMOA细胞拥有两种形式的ODC mRNA，它们被翻译成两种周转率差异很大的蛋白质。我们已将这两种ODC形式的cDNA克隆并转染到COS - 1细胞中，以直接测量它们的周转率。变异型ODC形式比野生型蛋白质稳定得多，半衰期为14小时，而野生型为2.5小时。
