Sorge J P, Sorge L K, Maness P F
Am J Pathol. 1985 Apr;119(1):151-7.
Human cells contain a tyrosine-specific protein kinase, pp60c-src, that is highly homologous to the oncogene product, pp60v-src, from Rous sarcoma virus but is of unknown function. The expression of human pp60c-src was examined in tissues obtained from human adults and fetuses of 20-32 weeks' gestational age. pp60c-src was quantitated in tissue extracts by measurement of its protein kinase activity by the use of the immune complex protein kinase assay. Brain showed the highest levels of pp60c-src protein kinase activity, but all other human tissues examined had significant levels. Fetal tissues, including brain, showed three- to eight-fold higher levels of pp60c-src kinase activity than the corresponding adult tissues. pp60c-src kinase was found to be uniformly distributed in the adult brain; frontal, occipital, and parietal cortex, and cerebellum expressed equivalent amounts of pp60c-src kinase activity. The protein kinase activity in human tissues exhibited properties characteristic of pp60c-src in other species, namely, tyrosine-specific phosphorylation of specific antibody heavy chains, autophosphorylation of a 60,000 Mr protein following immunoprecipitation with a monoclonal antibody specific for pp60src, and sensitivity to inhibition by P1,P4-di(adenosine-5')tetraphosphate. The high levels of human pp60c-src in fetal tissues, particularly in brain, suggest a possible function in developmental processes.
人类细胞含有一种酪氨酸特异性蛋白激酶pp60c-src，它与劳斯肉瘤病毒的癌基因产物pp60v-src高度同源，但功能未知。在取自20至32周胎龄的人类成人和胎儿的组织中检测了人类pp60c-src的表达。通过使用免疫复合物蛋白激酶测定法测量其蛋白激酶活性，对组织提取物中的pp60c-src进行定量。脑显示出最高水平的pp60c-src蛋白激酶活性，但所有其他检测的人体组织也有显著水平。包括脑在内的胎儿组织显示出的pp60c-src激酶活性水平比相应的成人组织高3至8倍。发现pp60c-src激酶在成人大脑中均匀分布；额叶、枕叶和顶叶皮质以及小脑表达等量的pp60c-src激酶活性。人体组织中的蛋白激酶活性表现出其他物种中pp60c-src的特性，即特异性抗体重链的酪氨酸特异性磷酸化、用对pp60src特异的单克隆抗体免疫沉淀后60,000 Mr蛋白的自身磷酸化以及对P1,P4-二（腺苷-5'）四磷酸抑制的敏感性。胎儿组织，尤其是脑中高水平的人类pp60c-src表明其在发育过程中可能具有某种功能。
