Tessier S, Chapdelaine A, Chevalier S
Maisonneuve-Rosemont Research Center, University of Montreal, Quebec, Canada.
Mol Cell Endocrinol. 1989 Sep;66(1):59-70. doi: 10.1016/0303-7207(89)90049-x.
To determine how functional changes such as growth and differentiation in the prostatic epithelium would alter protein phosphorylation on tyrosyl residues, differentiated (secretory) and basal (non-secretory) prostatic epithelial cells from normal and from metaplastic canine prostates were labeled with [32P]phosphate and their alkali-resistant phosphoproteins were analyzed by autoradiography after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The tyrosine protein kinase activity of the cells was also assayed by phosphorylation of a synthetic substrate, poly(Glu80-NaTyr20), in the presence of [gamma-32P]ATP. The prostates were characterized by tissue morphology and the cells by their density on Percoll gradients and [3H]thymidine incorporation into DNA. In prostates from intact dogs, tall columnar secretory epithelial cells were predominant and the non-secretory or basal epithelial cells were quiescent and did not incorporate [3H]thymidine. In metaplastic glands obtained from estrogen-treated castrated dogs, most of the isolated cells were non-secretory and synthesized DNA. Alkali-resistant phosphoproteins were present in all cell types. Except for two common phosphoproteins, p44 and p82, the relative phosphoprotein distribution within the gel differed when normal prostatic cells were compared to the metaplastic cells. However, the phosphoprotein patterns were the same in secretory and non-secretory cells from the same prostate tissue. On the other hand, the relative labeling intensity of phosphoproteins was always higher in non-secretory cells compared to corresponding secretory cells. Accordingly, tyrosine protein kinase (TPK) activity, expressed on a cell basis, was also higher in non-secretory cells; the ratios of TPK activities, non-secretory over corresponding secretory cells, was always higher than unity for all preparations but overlapped when cells from metaplastic glands were compared to those isolated from normal prostates. Thus, non-secretory epithelial cells isolated from either normal or metaplastic glands have a higher ability than corresponding secretory cells to phosphorylate endogenous alkali-resistant phosphoproteins and their TPK activity, measured with the synthetic substrate poly(Glu80-NaTyr20), is also higher.
为了确定前列腺上皮细胞中的生长和分化等功能变化如何改变酪氨酸残基上的蛋白质磷酸化，用[32P]磷酸盐标记来自正常和化生犬前列腺的分化（分泌性）和基底（非分泌性）前列腺上皮细胞，并在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳后通过放射自显影分析它们的耐碱磷蛋白。还通过在[γ-32P]ATP存在下合成底物聚（Glu80-NaTyr20）的磷酸化来测定细胞的酪氨酸蛋白激酶活性。通过组织形态学对前列腺进行表征，通过细胞在Percoll梯度上的密度以及[3H]胸苷掺入DNA来对细胞进行表征。在完整犬的前列腺中，高柱状分泌上皮细胞占主导，非分泌或基底上皮细胞静止且不掺入[3H]胸苷。在从经雌激素处理的去势犬获得的化生腺体中，大多数分离的细胞是非分泌性的且合成DNA。所有细胞类型中均存在耐碱磷蛋白。除了两种常见的磷蛋白p44和p82外，当将正常前列腺细胞与化生细胞进行比较时，凝胶内的相对磷蛋白分布有所不同。然而，来自同一前列腺组织的分泌性和非分泌性细胞中的磷蛋白模式相同。另一方面，与相应的分泌性细胞相比，非分泌性细胞中磷蛋白的相对标记强度总是更高。因此，以细胞为基础表达的酪氨酸蛋白激酶（TPK）活性在非分泌性细胞中也更高；对于所有制剂，非分泌性细胞与相应分泌性细胞的TPK活性之比总是高于1，但当将化生腺体的细胞与从正常前列腺分离的细胞进行比较时，该比值有重叠。因此，从正常或化生腺体中分离的非分泌性上皮细胞比相应的分泌性细胞具有更高的磷酸化内源性耐碱磷蛋白的能力，并且用合成底物聚（Glu80-NaTyr20）测量的它们的TPK活性也更高。
