Cross-talk between GlcNAcylation and phosphorylation:: Site-specific phosphorylation dynamics in response to globally elevated O-GlcNAc
Cross-talk between GlcNAcylation and phosphorylation:: Site-specific phosphorylation dynamics in response to globally elevated O-GlcNAc
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DOI：
10.1073/pnas.0806216105
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发表时间：
2008-09-16
影响因子：
11.1
通讯作者：
Hart, Gerald W.
中科院分区：
文献类型：
--
作者：
Wang, Zihao;Gucek, Marjan;Hart, Gerald W.
蛋白质GlcNAc酰化作为营养/应激传感器调节许多细胞核和细胞质蛋白质的功能。丝氨酸或苏氨酸残基上的O-GlcNAc循环（如磷酸化）几乎同样丰富，并且至少部分地通过其与磷酸化的相互作用发挥作用。在这里，我们描述的变化，在全球范围内升高GlcNAc酰化位点特异性磷酸化动力学。通过结合顺序磷酸残基富集，iTRAQ标记，和高通量质谱分析，磷酸化动力学上的711磷酸肽进行了定量。基于它们对磷酸酶抑制的不敏感性，我们得出结论，在研究条件下，这些磷酸化位点中约有48%没有活跃地循环。然而，增加GlcNAc酰化影响磷酸盐的化学计量在大多数的网站，似乎是积极的循环。升高的GlcNAc酰化导致280个位点的磷酸化降低，并导致148个位点的磷酸化增加。因此，这两种丰富的翻译后修饰之间的串扰或相互作用是广泛的，并且可能通过在相同或近端位点的空间占据竞争以及通过每个修饰调节另一个的酶机制而产生。由这一大组定量数据呈现的磷酸化蛋白质组动力学不仅描绘了磷酸化和GlcNAc化之间的复杂相互作用，而且还为O-GlcNAc在调节蛋白质功能和信号通路中的特定作用的更集中的研究提供了见解。
Protein GlcNAcylation serves as a nutrient/stress sensor to modulate the functions of many nuclear and cytoplasmic proteins. O-GlcNAc cycles on serine or threonine residues like phosphorylation, is nearly as abundant, and functions, at least partially, via its interplay with phosphorylation. Here, we describe changes in site-specific phosphorylation dynamics in response to globally elevated GlcNAcylation. By combining sequential phospho-residue enrichment, iTRAQ labeling, and high throughput mass spectrometric analyses, phosphorylation dynamics on 711 phosphopeptides were quantified. Based upon their insensitivity to phosphatase inhibition, we conclude that approximate to 48% of these phosphorylation sites were not actively cycling in the conditions of the study. However, increased GlcNAcylation influenced phosphate stoichiometry at most of the sites that did appear to be actively cycling. Elevated GlcNAcylation resulted in lower phosphorylation at 280 sites and caused increased phosphorylation at 148 sites. Thus, the cross-talk or interplay between these two abundant posttranslational modifications is extensive, and may arises both by steric competition for occupancy at the same or proximal sites and by each modification regulating the other's enzymatic machinery. The phosphoproteome dynamics presented by this large set of quantitative data not only delineates the complex interplay between phosphorylation and GlcNAcyation, but also provides insights for more focused investigations of specific roles of O-GlcNAc in regulating protein functions and signaling pathways.