MECHANISMS OF MEMBRANE FUNCTION IN CELL GROWTH

本申请寻求对一个研究项目的支持，该项目旨在更好地 了解质膜在调节生长中的作用， 培养细胞 拟议调查的具体目标是 研究四种膜相关的生理 参数（细胞膜电位，Ca +2内流，细胞cAMP水平，和 营养转运），其在正常细胞的有丝分裂原刺激后改变 以及细胞转化。 实验将寻求四个问题的解决方案 主要未解决的问题：首先，这四个膜参数的变化 它们是相互关联的还是独立改变的？ 第二， 有丝分裂原刺激或细胞的病毒转化诱导以下之一的变化： 这些参数会触发其他三个参数的变化？ 第三，纯化的有丝分裂原的结合是否刺激了这些细胞的变化， 通过直接影响膜功能或通过间接影响膜功能 刺激细胞代谢的变化，从而改变细胞膜 功能？ 第四，内部产生的生长因子是否通过病毒转化 细胞通过有丝分裂原受体影响膜功能？ 为回答这些问题而设计的实验包括测量 示踪分子穿过细胞膜和膜囊泡，以及 测量静止和静止时的cAMP浓度和膜电位， 有丝分裂原刺激的人成纤维细胞和其他哺乳动物细胞转化 一种对温度敏感的劳斯肉瘤病毒

This application seeks support for a research program directed toward a better understanding of the role of the plasma membrane in the regulation of growth in cultured cells. The specific objective of the proposed investigation is to examine the relationship between four membrane-associated, physiological parameters (cell membrane potential, Ca plus 2 influx, cell cAMP levels, and nutrient transport) which are altered upon mitogen stimulation of normal cells and upon cell transformation. The experiments will seek the solution to four major unsolved problems: First, are changes in these four membrane parameters causally interrelated or are they altered independently? Second, does mitogen-stimulation or viral transformation of cells induce a change in one of these parameters which then triggers changes in the other three parameters? Third, does the binding of purified mitogens stimulate changes in these parameters by directly influencing membrane function or indirectly by stimulating changes in cellular metabolism which act to modify membrane function? Fourth, do internally produced growth factors in virally transformed cells influence membrane function by acting through mitogen receptors? Experiments designed to answer these questions involve measurements of fluxes of tracer molecules across cellular membranes and membrane vesicles, and measurement of cAMP concentrations and membrane potentials in quiescent and mitogen-stimulated human fibroblasts and in other mammalian cells transformed by a temperature-sensitive Rous sarcoma virus.