Elucidating crosstalk mechanisms between phosphorylation and O-GlcNAcylation
Elucidating crosstalk mechanisms between phosphorylation and O-GlcNAcylation
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DOI：
10.1073/pnas.1620529114
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发表时间：
2017-08-29
影响因子：
11.1
通讯作者：
Heck, Albert J. R.
中科院分区：
文献类型：
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作者：
Leney, Aneika C.;El Atmioui, Dris;Heck, Albert J. R.
蛋白质可以通过多种翻译后修饰（PTM）进行修饰，从而创建一个控制蛋白质在空间和时间上功能的PTM代码。解开这种复杂的PTM密码是分子生物学的巨大挑战之一。在这里，使用基于质谱的分析，我们专注于最常见的ptms -磷酸化和o - glcn酰化-并研究它们如何相互影响。我们展示了两种通用的串声机制。首先，我们定义了一个频繁发生的、非常特殊和严格的磷酸化/O-GlcNAcylation相互作用基序（pSp/T） P(V/ a /T)(gS/gT)，磷酸化强烈抑制o - glcnac酰化。引人注目的是，这种严格的基序在人类（磷酸化）蛋白质组中大量富集，使我们能够预测数百种假定的O-GlcNAc转移酶（OGT）底物。我们进一步研究了其中的一组，并表明它们是OGT的良好底物，在P-3位点磷酸化时表现出负反馈回路。其次，我们证明在PX(S/T) P位点（即脯氨酸定向激酶磷酸化的位点）不发生互扰，而脯氨酸定向激酶占脊椎动物磷酸化蛋白质组中所有位点的40%。
Proteins can be modified by multiple posttranslational modifications (PTMs), creating a PTM code that controls the function of proteins in space and time. Unraveling this complex PTM code is one of the great challenges in molecular biology. Here, using mass spectrometry-based assays, we focus on the most common PTMs-phosphorylation and O-GlcNAcylation-and investigate how they affect each other. We demonstrate two generic crosstalk mechanisms. First, we define a frequently occurring, very specific and stringent phosphorylation/O-GlcNAcylation interplay motif, (pSp/T) P(V/A/T)(gS/gT), whereby phosphorylation strongly inhibits O-GlcNAcylation. Strikingly, this stringent motif is substantially enriched in the human (phospho) proteome, allowing us to predict hundreds of putative O-GlcNAc transferase (OGT) substrates. A set of these we investigate further and show them to be decent substrates of OGT, exhibiting a negative feedback loop when phosphorylated at the P-3 site. Second, we demonstrate that reciprocal crosstalk does not occur at PX(S/T) P sites, i.e., at sites phosphorylated by proline-directed kinases, which represent 40% of all sites in the vertebrate phosphoproteomes.