Baraban J M, Fiore R S, Sanghera J S, Paddon H B, Pelech S L
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
J Neurochem. 1993 Jan;60(1):330-6. doi: 10.1111/j.1471-4159.1993.tb05855.x.
Recent studies have demonstrated that administration of an electroconvulsive shock produces a rapid and transient increase in tyrosyl phosphorylation of a approximately 40-kDa protein in rat brain. Initial characterization of this protein's chromatographic properties indicated that it might be a member of a recently identified family of kinases, referred to as mitogen-activated protein (MAP) kinases, that are activated by tyrosyl phosphorylation. In the present study, we have used MAP kinase antisera to assess the identity of this protein. We have found that the approximately 40-kDa phosphotyrosine-containing protein comigrates with p42 MAP kinase (p42mapk) and not with two other 44-kDa MAP kinase family members detected by these antisera. Western blots of proteins immunoprecipitated with MAP kinase antibodies confirm that p42mapk displays increased tyrosyl phosphorylation after an electroconvulsive stimulus. Chromatographic separation of hippocampal extracts indicates that MAP kinase activity elutes in parallel with p42mapk. Accordingly, these studies identify p42mapk as a tyrosyl kinase substrate that is activated by this stimulus and suggest that this form of MAP kinase may be selectively regulated by neuronal stimulation.
最近的研究表明，给予电惊厥休克会使大鼠脑中一种约40 kDa的蛋白质的酪氨酸磷酸化迅速且短暂地增加。对该蛋白质色谱特性的初步表征表明，它可能是最近鉴定出的一类激酶家族的成员，称为丝裂原活化蛋白（MAP）激酶，其通过酪氨酸磷酸化被激活。在本研究中，我们使用MAP激酶抗血清来评估该蛋白质的身份。我们发现，约40 kDa含磷酸酪氨酸的蛋白质与p42 MAP激酶（p42mapk）迁移一致，而与这些抗血清检测到的其他两个44 kDa MAP激酶家族成员不一致。用MAP激酶抗体免疫沉淀的蛋白质的蛋白质免疫印迹证实，电惊厥刺激后p42mapk的酪氨酸磷酸化增加。海马提取物的色谱分离表明，MAP激酶活性与p42mapk平行洗脱。因此，这些研究确定p42mapk是一种被该刺激激活的酪氨酸激酶底物，并表明这种形式的MAP激酶可能受神经元刺激的选择性调节。
