Aitken A, Howell S, Jones D, Madrazo J, Patel Y
Laboratory of Protein Structure, National Institute for Medical Research, Mill Hill, London, United Kingdom.
J Biol Chem. 1995 Mar 17;270(11):5706-9. doi: 10.1074/jbc.270.11.5706.
The 14-3-3 protein family has received considerable attention recently in the literature, because of the finding that beta and zeta isoforms interact with and activate Raf. We had previously shown that these 14-3-3 isoforms also exist as phosphorylated forms in mammalian and avian brain. The presence of this modification enhances the activity of 14-3-3 as an inhibitor of protein kinase C nearly 2-fold. In this report we show by a combination of electrospray mass spectrometry and protein microsequencing that alpha and delta are in vivo post-translationally modified forms of beta and zeta, respectively, and the site of phosphorylation, serine 185, is in a consensus sequence motif for proline-directed kinases.
最近，14-3-3蛋白家族在文献中受到了相当多的关注，因为有研究发现β和ζ亚型与Raf相互作用并激活Raf。我们之前已经表明，这些14-3-3亚型在哺乳动物和鸟类大脑中也以磷酸化形式存在。这种修饰的存在使14-3-3作为蛋白激酶C抑制剂的活性提高了近2倍。在本报告中，我们通过电喷雾质谱和蛋白质微测序相结合的方法表明，α和δ分别是β和ζ的体内翻译后修饰形式，磷酸化位点丝氨酸185位于脯氨酸定向激酶的共有序列基序中。
