Bishayee S, Matesic D, Das M
Proc Natl Acad Sci U S A. 1984 Jun;81(11):3399-403. doi: 10.1073/pnas.81.11.3399.
We present evidence for a discrete 34,000-Da polypeptide with mitogenic activity, associated with plasma membranes from human A431 carcinoma cells. Plasma membranes from A431 cells are highly mitogenic for quiescent fibroblasts. A significant fraction of the membrane-associated activity can be released by treatment with a high concentration of salt and is relatively acid stable. Incubation of 125I-labeled salt-extracted proteins with target fibroblasts results in preferential binding of a 34,000-Da protein--i.e., greater than 90% of the cell-bound radioactivity is associated with the 34,000-Da polypeptide. Studies correlating the mitogenic activity with the cell-binding 34,000-Da protein indicate that this protein is the acid-stable, peripherally attached, mitogenically active component of A431 membranes. Available data suggest that this protein may be mitogenically active in the nanomolar concentration range. Some properties of this protein are described.
我们提供了证据，证明一种具有促有丝分裂活性的34,000道尔顿离散多肽与来自人A431癌细胞的质膜相关。A431细胞的质膜对静止的成纤维细胞具有高度促有丝分裂作用。很大一部分与膜相关的活性可以通过用高浓度盐处理而释放出来，并且相对耐酸。将125I标记的盐提取蛋白与靶成纤维细胞一起孵育，会导致一种34,000道尔顿的蛋白优先结合——即，超过90%的细胞结合放射性与34,000道尔顿的多肽相关。将促有丝分裂活性与细胞结合的34,000道尔顿蛋白相关联的研究表明，该蛋白是A431膜的耐酸、外周附着、具有促有丝分裂活性的成分。现有数据表明，该蛋白可能在纳摩尔浓度范围内具有促有丝分裂活性。本文描述了该蛋白的一些特性。
