mTORC2 controls the activity of PKC and Akt by phosphorylating a conserved TOR interaction motif.
mTORC2 controls the activity of PKC and Akt by phosphorylating a conserved TOR interaction motif.
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DOI：
10.1126/scisignal.abe4509
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发表时间：
2021-04-13
影响因子：
7.3
通讯作者：
Newton AC
中科院分区：
文献类型：
--
作者：
Baffi TR;Lordén G;Wozniak JM;Feichtner A;Yeung W;Kornev AP;King CC;Del Rio JC;Limaye AJ;Bogomolovas J;Gould CM;Chen J;Kennedy EJ;Kannan N;Gonzalez DJ;Stefan E;Taylor SS;Newton AC
激酶复合物mTORC 2被广泛认为是控制疏水基序磷酸化的蛋白激酶C（PKC）、Akt和其他AGC激酶C-末端尾部的关键调节开关。然而，它控制该位点的生化机制以及mTOR是否是直接的疏水基序激酶仍然存在争议。在这里，我们确定了一个独特的mTOR介导的磷酸化位点，我们称之为TOR相互作用基序（TIM; F-x3-F-pT），它控制疏水基序磷酸化和PKC和Akt的活性。TIM在所有mTOR依赖性激酶中是不变的，在进化上是保守的，并且与mTORC 2组分共同进化。Akt 1中该基序单独突变（Thr 443）或与PKCβII中的turn基序一起突变（Thr 634/Thr 641），通过损害激活环和疏水基序磷酸化来消除细胞激酶活性。mTORC 2在体外直接磷酸化PKC TIM，并通过质谱法在小鼠脑中检测其磷酸化。PDK 1在缺乏mTORC 2的细胞中的过表达通过依赖于其内在催化的机制来拯救PKC和Akt的疏水基序磷酸化，揭示了mTORC 2促进PDK 1磷酸化步骤，这反过来又允许自磷酸化。对先前报道的PKCβII晶体结构的分析揭示了由包含TIM的螺旋驱动的PKC同源二聚体。生物物理邻近分析表明，非磷酸化的PKC，但不是磷酸化的PKC，动态二聚化细胞。此外，通过钉合肽破坏二聚体界面促进疏水基序磷酸化。我们的数据支持mTORC 2通过TIM磷酸化缓解新生PKC二聚化的模型，募集PDK 1磷酸化激活环，并触发分子内疏水基序自磷酸化。TIM磷酸化及其在PKC调节中的作用的鉴定为mTORC 2调节AGC激酶提供了基础。mTORC 2结合并磷酸化PKC和Akt的C-尾中的保守TOR相互作用基序，以调节疏水基序自磷酸化和激酶活化。
The kinase complex mTORC2 is widely accepted as controlling phosphorylation of the hydrophobic motif, a key regulatory switch in the C-terminal tail of protein kinase C (PKC), Akt, and other AGC kinases. Yet the biochemical mechanism by which it controls this site and whether mTOR is the direct hydrophobic motif kinase remain controversial. Here we identify a distinct mTOR-mediated phosphorylation site we term the TOR-Interaction Motif (TIM; F-x3-F-pT), which controls hydrophobic motif phosphorylation and activity of PKC and Akt. The TIM is invariant in all mTOR-dependent kinases, is evolutionarily conserved, and co-evolved with mTORC2 components. Mutation of this motif alone in Akt1 (Thr443) or together with the turn motif in PKCβII (Thr634/Thr641) abolishes cellular kinase activity by impairing activation loop and hydrophobic motif phosphorylation. mTORC2 directly phosphorylates the PKC TIM in vitro, and its phosphorylation is detected in mouse brain by mass spectrometry. Overexpression of PDK1 in cells lacking mTORC2 rescues hydrophobic motif phosphorylation of PKC and Akt by a mechanism that depends on their intrinsic catalytic, revealing that mTORC2 facilitates the PDK1 phosphorylation step, which in turn permits autophosphorylation. Analysis of a previously reported PKCβII crystal structure reveals a PKC homodimer driven by a helix containing the TIM. Biophysical proximity assays show that unphosphorylated PKC, but not phosphorylated PKC, dynamically dimerizes in cells. Furthermore, disruption of the dimer interface by stapled peptides promotes hydrophobic motif phosphorylation. Our data support a model in which mTORC2 relieves nascent PKC dimerization through TIM phosphorylation, recruiting PDK1 to phosphorylate the activation loop, and triggering intramolecular hydrophobic motif autophosphorylation. Identification of TIM phosphorylation and its role in the regulation of PKC provides the basis for AGC kinase regulation by mTORC2. mTORC2 binds and phosphorylates a conserved TOR-Interaction Motif in the C-tail of PKC and Akt to regulate hydrophobic motif autophosphorylation and kinase activation.
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影响因子：
64.5
作者：
Antal CE;Hudson AM;Kang E;Zanca C;Wirth C;Stephenson NL;Trotter EW;Gallegos LL;Miller CJ;Furnari FB;Hunter T;Brognard J;Newton AC
通讯作者：
Newton AC
影响因子：
--
作者：
Antal, Corina E.;Violin, Jonathan D.;Newton, Alexandra C.
通讯作者：
Newton, Alexandra C.
影响因子：
4.8
作者：
Balasuriya, Nileeka;Kunkel, Maya T.;O'Donoghue, Patrick
通讯作者：
O'Donoghue, Patrick
影响因子：
11.4
作者：
Biondi, RM;Cheung, PCF;Alessi, DR
通讯作者：
Alessi, DR
影响因子：
4.8
作者：
Dries, Daniel R.;Gallegos, Lisa L.;Newton, Alexandra C.
通讯作者：
Newton, Alexandra C.