摘要
We have identified the p100 protein, previously known as a novel cellular coactivator, as a constituent of endoplasmic reticulum and cytosolic lipid droplets from milk secreting cells. Cytosolic lipid droplets of terminally differentiated mammary epithelial cells are secreted as milk lipid globules. However, milk lipid globules did not have detectable amounts of p100 protein. The p100 protein was found also in cytosol from lactating mammary gland, in storage lipid droplets from mouse adipocytes, and in endoplasmic reticulum from liver. Immunofluorescence microscopy of mammary epithelial cells confirmed the presence of p100 in non-nuclear regions of these cells. Partial sequence analysis of tryptic peptides from p100 from cow mammary gland showed extensive homology with the reported sequence of p100 determined from a human cDNA. Antibodies against a peptide synthesized to duplicate a sequence in human p100 recognized a protein of the size of p100 in cow, mouse and rat cell fractions.
摘要译文
我们已经确定了p100蛋白，以前称为新的细胞共激活因子，作为内质网和细胞质脂质液滴从乳汁分泌细胞的组成部分。终末分化的乳腺上皮细胞的细胞溶质脂滴作为乳脂质小球分泌。然而，乳脂质球没有可检测量的p100蛋白。在来自哺乳期乳腺的胞质溶胶，来自小鼠脂肪细胞的储存脂质液滴和来自肝脏的内质网中也发现p100蛋白质。乳腺上皮细胞的免疫荧光显微镜检查证实在这些细胞的非核区域中存在p100。来自牛乳腺的p100的胰蛋白酶肽的部分序列分析显示了与从人类cDNA测定的报道的p100序列的广泛同源性。针对合成以复制人p100中的序列的肽的抗体识别牛，小鼠和大鼠细胞部分中的p100大小的蛋白质。
Thomas W.Keenan[a];StefanieWinter[b];Hans-RichardRackwitz[b];Hans W.Heid[b];. Nuclear coactivator protein p100 is present in endoplasmic reticulum and lipid droplets of milk secreting cells[J]. Biochimica et Biophysica Acta (BBA) - General Subjects, 2000,1523(1): 84-90