Roles of constitutive and signal-dependent protein phosphatase 2A docking motifs in burst attenuation of the cyclic AMP response element-binding protein.
Roles of constitutive and signal-dependent protein phosphatase 2A docking motifs in burst attenuation of the cyclic AMP response element-binding protein.
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DOI：
10.1016/j.jbc.2021.100908
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发表时间：
2021-07
期刊：
影响因子：
--
通讯作者：
Tibbetts RS
中科院分区：
文献类型：
--
作者：
Kim SH;Wu CG;Jia W;Xing Y;Tibbetts RS
cAMP反应元件结合蛋白（CREB）是细胞生长、代谢和突触可塑性的重要调节因子。CREB是通过其内在无序激酶诱导结构域（KID）内进化上保守的丝氨酸残基（S133）的磷酸化激活的。响应cAMP、Ca2+和其他刺激的S133磷酸化触发KID与creb结合蛋白（CBP）的KID相互作用（KIX）结构域的关联，creb结合蛋白（CBP）是一种促进转录激活的组蛋白乙酰转移酶（HAT）。在这里，我们研究了CREB磷酸化爆发后CREB衰减的机制。我们发现S133的磷酸化被蛋白磷酸酶2A （PP2A）逆转，PP2A通过其B56调控亚基被募集到CREB中。我们发现，位于KID羧基端边界的B56结合位点（BS2）介导高亲和力的B56结合，而位于KID氨基端附近的第二个结合位点（BS1）介导低亲和力结合，通过相邻酪蛋白激酶（CK）磷酸位点的磷酸化增强。减少B56与BS2结合的突变增加了S133的基础磷酸化和刺激诱导磷酸化，增加了CBP与CREB的相互作用，并增强了CREB依赖性报告基因的表达。携带破坏BS2的纯合子CrebE153D突变的小鼠细胞表现出增加的S133磷酸化化学计量学和增加的cAMP转录爆发。这些发现为PP2A全酶靶向底物提供了新的见解，并建立了CREB衰减的新机制，这对理解细胞生长、代谢、突触可塑性和其他生理环境中的CREB信号传导具有重要意义。
The cAMP response element-binding protein (CREB) is an important regulator of cell growth, metabolism, and synaptic plasticity. CREB is activated through phosphorylation of an evolutionarily conserved Ser residue (S133) within its intrinsically disordered kinase-inducible domain (KID). Phosphorylation of S133 in response to cAMP, Ca2+, and other stimuli triggers an association of the KID with the KID-interacting (KIX) domain of the CREB-binding protein (CBP), a histone acetyl transferase (HAT) that promotes transcriptional activation. Here we addressed the mechanisms of CREB attenuation following bursts in CREB phosphorylation. We show that phosphorylation of S133 is reversed by protein phosphatase 2A (PP2A), which is recruited to CREB through its B56 regulatory subunits. We found that a B56-binding site located at the carboxyl-terminal boundary of the KID (BS2) mediates high-affinity B56 binding, while a second binding site (BS1) located near the amino terminus of the KID mediates low affinity binding enhanced by phosphorylation of adjacent casein kinase (CK) phosphosites. Mutations that diminished B56 binding to BS2 elevated both basal and stimulus-induced phosphorylation of S133, increased CBP interaction with CREB, and potentiated the expression of CREB-dependent reporter genes. Cells from mice harboring a homozygous CrebE153D mutation that disrupts BS2 exhibited increased S133 phosphorylation stoichiometry and elevated transcriptional bursts to cAMP. These findings provide insights into substrate targeting by PP2A holoenzymes and establish a new mechanism of CREB attenuation that has implications for understanding CREB signaling in cell growth, metabolism, synaptic plasticity, and other physiologic contexts.
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DOI：
10.1038/nrm3072
发表时间：
2011-03
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
影响因子：
3.5
作者：
Arthur, JSC;Cohen, P
通讯作者：
Cohen, P
DOI：
10.1073/pnas.1219028109
发表时间：
2012-12-18
影响因子：
11.1
作者：
Luo, Qianyi;Viste, Kristin;Radhakrishnan, Ishwar
通讯作者：
Radhakrishnan, Ishwar
DOI：
10.1073/pnas.1932773100
发表时间：
2003-10-14
影响因子：
11.1
作者：
Iourgenko, V;Zhang, WJ;Labow, MA
通讯作者：
Labow, MA
影响因子：
11.4
作者：
Ravnskjaer, Kim;Kester, Henri;Montminy, Marc
通讯作者：
Montminy, Marc