2014 Vol. 5, No. 12

Vantage points
FMRP: a new chapter with chromatin
Qingzhong He, Wei Ge
2014, 5(12): 885-888. doi: 10.1007/s13238-014-0105-5
Understanding the genetic and epigenetic architecture in complex network of rice flowering pathways
Changhui Sun, Dan Chen, Jun Fang, Pingrong Wang, Xiaojian Deng, Chengcai Chu
2014, 5(12): 889-898. doi: 10.1007/s13238-014-0068-6
Although the molecular basis of flowering time control is well dissected in the long day (LD) plant Arabidopsis, it is still largely unknown in the short day (SD) plant rice. Rice flowering time (heading date) is an important agronomic trait for season adaption and grain yield, which is affected by both genetic and environmental factors. During the last decade, as the nature of florigen was identified, notable progress has been made on exploration how florigen gene expression is genetically controlled. In Arabidopsis expression of certain key flowering integrators such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT) are also epigenetically regulated by various chromatin modifications, however, very little is known in rice on this aspect until very recently. This review summarized the advances of both genetic networks and chromatin modifications in rice flowering time control, attempting to give a complete view of the genetic and epigenetic architecture in complex network of rice flowering pathways.
Recent advances in the role of toll-like receptors and TLR agonists in immunotherapy for human glioma
Shuanglin Deng, Shan Zhu, Yuan Qiao, Yong-Jun Liu, Wei Chen, Gang Zhao, Jingtao Chen
2014, 5(12): 899-911. doi: 10.1007/s13238-014-0112-6
Gliomas are extremely aggressive brain tumors with a very poor prognosis. One of the more promising strategies for the treatment of human gliomas is targeted immunotherapy where antigens that are unique to the tumors are exploited to generate vaccines. The approach, however, is complicated by the fact that human gliomas escape immune surveillance by creating an immune suppressed microenvironment. In order to oppose the glioma imposed immune suppression, molecules and pathways involved in immune cell maturation, expansion, and migration are under intensive clinical investigation as adjuvant therapy. Toll-like receptors (TLRs) mediate many of these functions in immune cell types, and TLR agonists, thus, are currently primary candidate molecules to be used as important adjuvants in a variety of cancers. In animal models for glioma, TLR agonists have exhibited antitumor properties by facilitating antigen presentation and stimulating innate and adaptive immunity. In clinical trials, several TLR agonists have achieved survival benefit, and many more trials are recruiting or ongoing. However, a second complicating factor is that TLRs are also expressed on cancer cells where they can participate instead in a variety of tumor promoting activities including cell growth, proliferation, invasion, migration, and even stem cell maintenance. TLR agonists can, therefore, possibly play dual roles in tumor biology. Here, how TLRs and TLR agonists function in glioma biology and in anti-glioma therapies is summarized in an effort to provide a current picture of the sophisticated relationship of glioma with the immune system and the implications for immunotherapy.
Research articles
Coronavirus membrane-associated papain-like proteases induce autophagy through interacting with Beclin1 to negatively regulate antiviral innate immunity
Xiaojuan Chen, Kai Wang, Yaling Xing, Jian Tu, Xingxing Yang, Qian Zhao, Kui Li, Zhongbin Chen
2014, 5(12): 912-927. doi: 10.1007/s13238-014-0104-6
Autophagy plays important roles in modulating viral replication and antiviral immune response. Coronavirus infection is associated with the autophagic process, however, little is known about the mechanisms of autophagy induction and its contribution to coronavirus regulation of host innate responses. Here, we show that the membrane-associated papain-like protease PLP2 (PLP2-TM) of coronaviruses acts as a novel autophagyinducing protein. Intriguingly, PLP2-TM induces incomplete autophagy process by increasing the accumulation of autophagosomes but blocking the fusion of autophagosomes with lysosomes. Furthermore, PLP2-TM interacts with the key autophagy regulators, LC3 and Beclin1, and promotes Beclin1 interaction with STING, the key regulator for antiviral IFN signaling. Finally, knockdown of Beclin1 partially reverses PLP2-TM's inhibitory effect on innate immunity which resulting in decreased coronavirus replication. These results suggested that coronavirus papain-like protease induces incomplete autophagy by interacting with Beclin1, which in turn modulates coronavirus replication and antiviral innate immunity.
A new glimpse of FadR-DNA crosstalk revealed by deep dissection of the E. coli FadR regulatory protein
Yongchang Zhang, Rongsui Gao, Huiyan Ye, Qingjing Wang, Youjun Feng
2014, 5(12): 928-939. doi: 10.1007/s13238-014-0107-3
Escherichia coli (E. coli) FadR regulator plays dual roles in fatty acid metabolism, which not only represses the fatty acid degradation (fad) system, but also activates the unsaturated fatty acid synthesis pathway. Earlier structural and biochemical studies of FadR protein have provided insights into interplay between FadR protein with its DNA target and/or ligand, while the missing knowledge gap (esp. residues with indirect roles in DNA binding) remains unclear. Here we report this case through deep mapping of old E. coli fadR mutants accumulated. Molecular dissection of E. coli K113 strain, a fadR mutant that can grow on decanoic acid (C10) as sole carbon sources unexpectedly revealed a single point mutation of T178G in fadR locus (W60G in FadRk113). We also observed that a single geneticallyrecessive mutation of W60G in FadR regulatory protein can lead to loss of its DNA-binding activity, and thereby impair all the regulatory roles in fatty acid metabolisms. Structural analyses of FadR protein indicated that the hydrophobic interaction amongst the three amino acids (W60, F74 and W75) is critical for its DNA-binding ability by maintaining the configuration of its neighboring two β-sheets. Further site-directed mutagenesis analyses demonstrated that the FadR mutants (F74G and/or W75G) do not exhibit the detected DNA-binding activity, validating above structural reasoning.
Transcriptional regulation of the waaAE-coaD operon by PhoP and RcsAB in Yersinia pestis biovar Microtus
Lei Liu, Nan Fang, Yicheng Sun, Huiying Yang, Yiquan Zhang, Yanping Han, Dongsheng Zhou, Ruifu Yang
2014, 5(12): 940-944. doi: 10.1007/s13238-014-0110-8
11'-Deoxyverticillin A (C42) promotes autophagy through K-Ras/GSK3 signaling pathway in HCT116 cells
Shubin Niu, Dongdong Yuan, Xuejun Jiang, Yongsheng Che
2014, 5(12): 945-949. doi: 10.1007/s13238-014-0099-z
Investigation of a special neutralizing epitope of HEV E2s
Min You, Lu Xin, Yi Yang, Xiao Zhang, Yingwei Chen, Hai Yu, Shaowei Li, Jun Zhang, Zhiqiang An, Wenxin Luo, Ningshao Xia
2014, 5(12): 950-953. doi: 10.1007/s13238-014-0115-3
Characterization of the amino-terminal domain of Mx2/MxB-dependent interaction with the HIV-1 capsid
Jia Kong, Bo Xu, Wei Wei, Xin Wang, Wei Xie, Xiao-Fang Yu
2014, 5(12): 954-957. doi: 10.1007/s13238-014-0113-5