Prasad G L, Valverius E M, McDuffie E, Cooper H L
Cell and Molecular Physiology Section, National Cancer Institute, Bethesda, Maryland 20892.
Cell Growth Differ. 1992 Aug;3(8):507-13.
A full-length complementary DNA clone from a normal human mammary epithelial cell (strain 184) encoding a 25-kilodalton protein, HME1, was isolated. Expression of HME1 RNA appears to be limited to epithelial cells. The HME1 sequence has extensive sequence homology with bovine 14-3-3 protein, which is an activator of tyrosine and tryptophan hydroxylase. However, the tissue distribution, arrangement of charged amino acids, and location of potential phosphorylation sites of HME1 differ from those of 14-3-3. Compared with normal mammary epithelial cells, expression of HME1 RNA was dramatically low in two cell lines derived from human mammary carcinoma that were examined, and in a line of normal mammary epithelial cells transformed by oncogenes. HME1 therefore appears to be a cellular differentiation marker that may be down-regulated during neoplastic transformation.
从一株正常人类乳腺上皮细胞（184株）中分离出一个全长互补DNA克隆，它编码一种25千道尔顿的蛋白质HME1。HME1 RNA的表达似乎仅限于上皮细胞。HME1序列与牛14-3-3蛋白具有广泛的序列同源性，牛14-3-3蛋白是酪氨酸和色氨酸羟化酶的激活剂。然而，HME1的组织分布、带电荷氨基酸的排列以及潜在磷酸化位点的位置与14-3-3不同。与正常乳腺上皮细胞相比，在所检测的源自人乳腺癌的两个细胞系以及经癌基因转化的正常乳腺上皮细胞系中，HME1 RNA的表达显著降低。因此，HME1似乎是一种细胞分化标志物，在肿瘤转化过程中可能会下调。
