The Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Life Sci. 2010 Dec 18;87(23-26):667-71. doi: 10.1016/j.lfs.2010.09.021. Epub 2010 Sep 29.
To determine whether protein acylation plays a role in the effects of glucose on the insulin secreting β-cell.
The measurement of (3)H-palmitate incorporation into protein in the INS 832/13 cell that has a robust and well-characterized biphasic insulin secretory response to stimulation with glucose.
Stimulating the cells with glucose increased the incorporation of (3)H-palmitic acid into protein by up to 90%. Similarly, 2-aminobicyclo [2.2.1] heptane-2-carboxylic acid (BCH) the non-metabolizable analog of leucine that mimics the stimulatory effect of glucose on insulin secretion also increased the incorporation of (3)H-palmitic acid into protein. Treatment of cell lysates with hydroxylamine substantially reduced the incorporation indicating that most of the incorporation was due to enzymatic palmitoylation of proteins. Cerulenin, a classical inhibitor of protein acylation also substantially reduced the incorporation. Using PAGE and autoradiography a glucose-induced increase in protein palmitoylation and specific glucose-induced increases in the palmitoylation of proteins of 30, 44, 48 and 76kD were identified.
The data suggest that protein acylation plays multiple roles in β-cell function.
确定蛋白质酰化是否在葡萄糖对胰岛素分泌β细胞的作用中发挥作用。
测量 INS 832/13 细胞中(3)H-软脂酸掺入蛋白质的情况,该细胞对葡萄糖的刺激具有强大且特征明确的双相胰岛素分泌反应。
刺激细胞使(3)H-软脂酸掺入蛋白质的量增加了多达 90%。同样,2-氨基双环[2.2.1]庚烷-2-羧酸(BCH)是亮氨酸的不可代谢类似物,可模拟葡萄糖对胰岛素分泌的刺激作用,也增加了(3)H-软脂酸掺入蛋白质的量。用羟胺处理细胞裂解物可大大减少掺入量,表明大部分掺入是由于蛋白质的酶促棕榈酰化。棒曲霉素是一种经典的蛋白质酰化抑制剂,也大大减少了掺入量。使用 PAGE 和放射自显影技术,发现葡萄糖诱导的蛋白质棕榈酰化增加,以及特定的葡萄糖诱导的 30、44、48 和 76kD 蛋白质的棕榈酰化增加。
数据表明蛋白质酰化在β细胞功能中发挥多种作用。