Pelech S L, Charest D L
Biomedical Research Centre, University of British Columbia, Vancouver, Canada.
Prog Cell Cycle Res. 1995;1:33-52. doi: 10.1007/978-1-4615-1809-9_4.
Mitogen-activated protein kinases such as Erk1 and Erk2 serve as a paradigm for a growing family of proline-directed protein kinases that mediate entry, progression and exit from the cell cycle in diverse eukaryotic cells. These enzymes function within highly conserved modules of sequentially activating protein kinases that transduce signals from diverse extracellular stimuli. In vertebrates, at least three distinct kinases modules have been characterized. Mitogens induce the sequential activation of the kinases Raf1-->Mek1-->Erk2-->Rsk via the G-protein Ras. Stress factors stimulate c-Jun activation through a related kinase pathway involving Mekk-->Sek-->SAPK c-Jun, and hsp27 phosphorylation via the MKK3-->Hog-->MAPKAPK-2 hsp27 route. Genetic and biochemical studies, for example from budding yeast, imply the existence of several related protein kinase modules that can operate in parallel or within integrated systems.
丝裂原活化蛋白激酶，如Erk1和Erk2，是脯氨酸定向蛋白激酶家族不断发展的一个范例，该家族介导多种真核细胞进入、进行和退出细胞周期。这些酶在高度保守的顺序激活蛋白激酶模块中发挥作用，这些模块从不同的细胞外刺激转导信号。在脊椎动物中，至少已经鉴定出三种不同的激酶模块。丝裂原通过G蛋白Ras诱导激酶Raf1→Mek1→Erk2→Rsk的顺序激活。应激因子通过涉及Mekk→Sek→SAPK c-Jun的相关激酶途径刺激c-Jun激活，并通过MKK3→Hog→MAPKAPK-2 hsp27途径刺激hsp27磷酸化。例如来自芽殖酵母的遗传和生化研究表明，存在几个相关的蛋白激酶模块，它们可以并行运行或在整合系统中运行。
