Clifton A D, Young P R, Cohen P
MRC Protein Phosphorylation Unit, Department of Biochemistry, University of Dundee, Scotland, UK.
FEBS Lett. 1996 Sep 2;392(3):209-14. doi: 10.1016/0014-5793(96)00816-2.
MAPKAP kinase-2 and MAPKAP kinase-3 were both activated in response to cellular stress, interleukin-1 and tumour necrosis factor in KB and HeLa cells, and with identical kinetics. Activation of MAPKAP kinase-3, like MAPKAP kinase-2, was prevented by SB 203580, a specific inhibitor of SAPK-2, the upstream activator of MAPKAP kinase-2. MAPKAP kinase-3 and MAPKAP kinase-2 phosphorylated peptide substrates with similar kinetic constants and phosphorylated the same serine residues in HSP27 at the same relative rates. These results establish that MAPKAP kinase-3 lies 'downstream' of SAPK-2 and that it is likely to have overlapping or identical substrates to MAPKAP kinase-2 in vivo.
在KB和HeLa细胞中，丝裂原活化蛋白激酶相关激酶-2（MAPKAP kinase-2）和丝裂原活化蛋白激酶相关激酶-3（MAPKAP kinase-3）在细胞应激、白细胞介素-1和肿瘤坏死因子的作用下均被激活，且动力学相同。与MAPKAP kinase-2一样，MAPKAP kinase-3的激活也被SB 203580所抑制，SB 203580是MAPKAP kinase-2的上游激活剂SAPK-2的特异性抑制剂。MAPKAP kinase-3和MAPKAP kinase-2磷酸化肽底物的动力学常数相似，并以相同的相对速率磷酸化热休克蛋白27（HSP27）中的相同丝氨酸残基。这些结果表明，MAPKAP kinase-3位于SAPK-2的“下游”，并且在体内它可能与MAPKAP kinase-2具有重叠或相同的底物。
