Takeda A, Maizel A L
Department of Pathology, Roger Williams General Hospital, Brown University, Providence, RI 02908.
Science. 1990 Nov 2;250(4981):676-9. doi: 10.1126/science.2146743.
Some protein kinases and phosphatases are myristoylated on their amino terminus, which perhaps contributes to subcellular localization or regulation. Glycoprotein CD45, a hematopoietic tyrosine phosphatase, was examined for fatty acid content. The CD45 protein incorporated [3H]myristate, but little [3H]palmitate. The label was not metabolized and reincorporated into amino acids or saccharides, as revealed by peptide maps of CD45 labeled with [3H]myristate, 14C-labeled amino acids, [35S]methionine, or 125I, and glycosidase treatments, respectively. The myristate label was resistant to mild alkaline methanolysis and was found in fatty acid and sphingosine, indicating an unusual form of lipid attachment to CD45.
一些蛋白激酶和磷酸酶在其氨基末端发生肉豆蔻酰化，这可能有助于亚细胞定位或调节。对造血酪氨酸磷酸酶糖蛋白CD45的脂肪酸含量进行了检测。CD45蛋白掺入了[3H]肉豆蔻酸，但掺入的[3H]棕榈酸很少。如分别用[3H]肉豆蔻酸、14C标记的氨基酸、[35S]甲硫氨酸或125I标记的CD45的肽图以及糖苷酶处理所显示，该标记未被代谢并重新掺入氨基酸或糖类中。肉豆蔻酸标记对温和碱性甲醇解具有抗性，且存在于脂肪酸和鞘氨醇中，表明CD45存在一种不同寻常的脂质连接形式。
