EXPRESSION OF CARBOHYDRATE BINDING PROTEIN-35 IN HUMAN FIBROBLASTS - VARIATIONS IN THE LEVELS OF MESSENGER-RNA, PROTEIN, AND ISOELECTRIC SPECIES AS A FUNCTION OF REPLICATIVE COMPETENCE
EXPRESSION OF CARBOHYDRATE BINDING PROTEIN-35 IN HUMAN FIBROBLASTS - VARIATIONS IN THE LEVELS OF MESSENGER-RNA, PROTEIN, AND ISOELECTRIC SPECIES AS A FUNCTION OF REPLICATIVE COMPETENCE
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DOI：
10.1016/0014-4827(91)90458-7
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发表时间：
1991-09-01
影响因子：
3.7
通讯作者：
ANDERSON, RL
中科院分区：
文献类型：
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作者：
HAMANN, KK;COWLES, EA;ANDERSON, RL
我们比较了不同复制能力的人 SL66 成纤维细胞中碳水化合物结合蛋白 35 (CBP35) 的表达和定位。当血清饥饿、静止的年轻细胞（第 11 代，相当于约 18 次累积群体倍增）SL66 细胞用血清处理时，CBP35 的表达受到显着刺激。这通过免疫荧光下抗 CBP35 阳性染色的细胞百分比的增加、免疫印迹中蛋白质含量的增加以及 Northern 印迹中积累的 mRNA 水平的增加来揭示。增殖细胞中 CBP35 表达的升高在核部分中表现得最为明显，非磷酸化 (pI8.7) 蛋白以及磷酸化 (pI8.2) 衍生物的水平升高。相比之下，较旧的（第 27-35 代、第 55-68 代累积群体倍增）SL66 成纤维细胞培养物似乎已经失去了 CBP35 表达的正常增殖依赖性调节。 CBP35的水平在静止的高传代细胞中较高，并且在血清刺激后有所下降。此外，在高传代 SL66 细胞的细胞核或细胞质中均未检测到非磷酸化 (pI8.7) 形式的凝集素。最后，CBP35 mRNA 水平在高传代细胞的静止培养物中很高，但在血清刺激后 17 小时检测不到。这些结果证实，随着人成纤维细胞复制能力的降低，CBP35 的表达发生改变。
We have compared the expression and localization of carbohydrate binding protein 35 (CBP35) in human SL66 fibroblasts of different replicative capacities. When serum-starved, quiescent young (passage 11, corresponding to ~18 cumulative population doublings) SL66 cells were treated with serum, there was a marked stimulation in the expression of CBP35. This was revealed both by an increase in the percentage of cells positively stained with anti-CBP35 under immunofluorescence and by an increase in the amount of the protein in immunoblots, as well as by an increase in the level of accumulated mRNA in Northern blots. The rise in the expression of CBP35 in proliferating cells was manifested most clearly in the nuclear fraction, with elevation in the levels of the nonphosphorylated (pI8.7) protein, as well as the phosphorylated (pI8.2) derivative. In contrast, older (passage 27–35, 55–68 cumulative population doublings) cultures of SL66 fibroblasts appear to have lost the normal proliferation-dependent regulation of CBP35 expression. The level of CBP35 was high in quiescent high-passage cells and decreased somewhat after serum stimulation. Furthermore, the unphosphorylated (pI8.7) form of the lectin could not be detected in either the nucleus or the cytoplasm of high-passage SL66 cells. Finally, the level of the mRNA for CBP35 was high in quiescent cultures of high-passage cells, but undetectable 17 h after serum stimulation. These results establish that the expression of CBP35 becomes altered as human fibroblasts acquire reduced replicative capacity.