The Dengue virus protease NS2B3 cleaves cyclic GMP-AMP synthase to suppress cGAS activation.
The Dengue virus protease NS2B3 cleaves cyclic GMP-AMP synthase to suppress cGAS activation.
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DOI：
10.1016/j.jbc.2023.102986
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发表时间：
2023-03
期刊：
影响因子：
--
通讯作者：
Yin Q
中科院分区：
文献类型：
--
作者：
Bhattacharya M;Bhowmik D;Tian Y;He H;Zhu F;Yin Q
登革病毒(DENV)是最流行的蚊媒人类病毒之一，在世界范围内导致显著的发病率和死亡率。为了在细胞中持续存在并因此导致疾病，DENV的进化具有通过拮抗cGAS-STING信号来抑制I型干扰素诱导的机制。利用重组蛋白和体外切割实验，我们证明了DENV蛋白酶NS2B3能够在不破坏C末端催化中心的情况下切割N-末端区域的cGAs。这会产生两种主要的切割产物：切割产物N-端(CP-N)和切割产物C-端(CP-C)。我们观察到与全长cGAs相比，CP-C的DNA结合亲和力降低。DNA结合亲和力的降低也与CP-C酶活性的降低有关。另一方面，CP-N与DNA的结合能力几乎与全长cGAs相当。事实上，Cp-N通过全长cGAs和Cp-C竞争性地抑制循环GMP-AMP的产生。我们推测，CP-N的高DNA结合亲和力使其能够从CP-C和未切割的全长cGAs中分离DNA，从而降低酶激活和循环GMP-AMP合成的速度。此外，我们发现NS2B3与全长cGAs和CP-C在物理上相互作用，为它们穿梭到自噬体内并最终降解奠定了基础。总体而言，我们的研究强调了一种多方面的有效策略，通过该策略，RNA病毒可以对抗cGAS-STING信号，这可能有助于设计针对病毒蛋白酶的抗病毒药物。
Dengue virus (DENV) is one of the most prevalent mosquito-transmitted human viruses that causes significant morbidity and mortality worldwide. To persist in the cell and consequently cause disease, DENV is evolved with mechanisms to suppress the induction of type I interferons by antagonizing cGAS-STING signaling. Using recombinant proteins and in vitro cleavage assays, we have shown that the DENV protease NS2B3 is capable of cleaving cGAS in the N-terminal region without disrupting the C-terminal catalytic center. This generates two major cleavage products: cleavage product N-terminal (CP-N) and cleavage product C-terminal (CP-C). We observed reduction in DNA-binding affinity of CP-C as compared to full-length cGAS. Reduction in DNA-binding affinity is also correlated with the decrease in enzymatic activity of CP-C. CP-N, on the other hand, has almost comparable DNA-binding ability as that of the full-length cGAS. In fact, CP-N competitively inhibits cyclic GMP-AMP production by both full-length cGAS and CP-C. We hypothesize that high DNA-binding affinity of CP-N enables it to sequester the DNA from CP-C and noncleaved full-length cGAS and thus reduces the rate of enzyme activation and cyclic GMP-AMP synthesis. Furthermore, we found that NS2B3 physically interacts with full-length cGAS and CP-C, laying the basis for their shuttling to and eventual degradation in the autophagosome. Overall, our study highlights a multifaceted and effective strategy by which an RNA virus antagonizes cGAS-STING signaling which may be useful for the design of antivirals targeting viral proteases.
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DOI：
10.1073/pnas.2200285119
发表时间：
2022-08-16
影响因子：
11.1
作者：
通讯作者：
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影响因子：
16.8
作者：
Erbel, P;Schiering, N;Hommel, U
通讯作者：
Hommel, U
影响因子：
2.9
作者：
Askenasy, Isabel;Murray, Daniel T.;Stroupe, M. Elizabeth
通讯作者：
Stroupe, M. Elizabeth
影响因子：
8
作者：
Aleshin, Alexander E.;Shiryaev, Sergey A.;Liddington, Robert C.
通讯作者：
Liddington, Robert C.
影响因子：
64.5
作者：
Barnett, Katherine C.;Coronas-Serna, Julia M.;Kagan, Jonathan C.
通讯作者：
Kagan, Jonathan C.