Cross-talking between autophagy and viral infection in mammalian cells

Autophagy is a cellular process in degradation of long-lived proteins and organelles in the cytosol for maintaining cellular homeostasis, which has been linked to a wide range of human health and disease states, including viral infection. The viral infected cells exhibit a complicated cross-talking between autophagy and virus. It has been shown that autophagy interacts with both adaptive and innate immunity. For adaptive immunity, viral antigens can be processed in autophagosomes by acidic proteases before major histocompatibility complex (MHC) class II presentation. For innate immunity, autophagy may assist in the delivery of viral nucleic acids to endosomal TLRs and also functions as a part of the TLR-or-PKR-downstream responses. Autophagy was also reported to suppress the magnitude of host innate antiviral immunity in certain cases. On the other hand, viruses has evolved many strategies to combat or utilize the host autophagy for their own benefit. In this review we discussed recent advances toward clarifying the cross-talking between autophagy and viral infection in mammalian cells.     

Evolutionarily conserved DELLA-mediated gibberellin signaling in plants

Gibberellins (GAs) play important roles in many essential plant growth and development processes. A family of nuclear growth-repressing DELLA proteins is the key component in GA signaling. GA perception is mediated by GID1, and the key event of GA signaling is the degradation of DELLA proteins via the 26S proteasome pathway. DELLA proteins integrating other plant hormones signaling and environmental cue modulating plant growth and development have been revealed. GA turning on the de-DELLA-repressing system is conserved, and independently establishes step-by-step recruitment of GA-stimulated GID1-DELLA interaction and DELLA growth-repression functions during land plant evolution. These discoveries open new prospects for the understanding of GA action and DELLA-mediated signaling in plants.     

昆虫细胞程序性死亡的研究进展

在昆虫发育和抵抗病原微生物的入侵过程中,细胞凋亡与自噬性死亡现象十分常见。昆虫细胞凋亡的研究已经取得了许多的成果,但是有关细胞自噬程序性死亡的研究还正在深入。昆虫细胞凋亡的信号通路至少有3条：一条类似于线虫细胞的凋亡信号通路,另一条类似于哺乳动物细胞的凋亡信号通路, 还有一条不依赖于胱天蛋白酶的凋亡信号通路。在昆虫的多种组织细胞中,细胞凋亡与自噬程序性死亡在信号通路上存在互串(cross talking),可以相互促进、抑制或替代。了解昆虫细胞程序性死亡对防治害虫具有一定的意义。     

Changing concepts in plant hormone action

Summary A plant hormone is not, in the classic animal sense, a chemical synthesized in one organ, transported to a second organ to exert a chemical action to control a physiological event. Any phytohormone can be synthesized everywhere and can influence different growth and development processes at different places. The concept of physiological activity under hormonal control cannot be dissociated from changes in concentrations at the site of action, from spatial differences and changes in the tissue's sensitivity to the compound, from its transport and its metabolism, from balances and interactions with the other phytohormones, or in their metabolic relationships, and in their signaling pathways as well. Secondary messengers are also involved. Hormonal involvement in physiological processes can appear through several distinct manifestations (as environmental sensors, homeostatic regulators and spatio-temporal synchronizers, resource allocators, biotime adjusters, etc.), dependent on or integrated with the primary biochemical pathways. The time has also passed for the hypothesized ‘specific’ developmental hormones, rhizocaline, canlocaline, and florigen: root, stem, and flower formation result from a sequential control of specific events at the right places through a coordinated control by electrical signals, the known phytohormones and nonspecific molecules of primary and secondary metabolism, and involve both cytoplasmic and apoplastic compartments. These contemporary views are examined in this review.     

Evolutionarilv Conserved DELLA-mediated Gibberellin Signaling in Plants

Gibberellins (GAs) play important roles in many essential plant growth and development processes. A family of nuclear growth-repressing DELLA proteins is the key component in GA signaling. GA perception is mediated by GID1, and the key event of GA signaling is the degradation of DELLA proteins via the 26S proteasome pathway. DELLA proteins integrating other plant hormones signaling and environmental cue modulating plant growth and development have been revealed. GA turning on the de-DELLA-repressing system is conserved, and independently establishes step-by-step recruitment of GAstimulated GID1-DELLA interaction and DELLA growth-repression functions during land plant evolution. These discoveries open new prospects for the understanding of GA action and DELLA-mediated signaling in plants.     

赤霉素作用机理的分子基础与调控模式研究进展

赤霉素（gibberellins或gibberellic acid,GA）作为植物生长的必需激素之一,调控植物生长发育的各个方面,如：种子萌发,下胚轴的伸长,叶片的生长和植物开花时间等。近年来随着植物功能基因组学的进一步发展,有关赤霉素生物合成及其调控,赤霉素信号转导途径,以及赤霉素与其他激素和环境因子的互作等领域的研究取得了较大的进展。本文综述了赤霉素生物合成的生物学途径及其调控研究;GA信号转导通道的研究进展,特别是DELLA蛋白阻遏植物生长发育的分子机理和GA解除阻遏作用（derepress）的分子模型;GA受体研究的新进展;探讨GA与其它激素之间的相互作用,以及植物在应答环境过程中的作用。