Language anxiety is independent of other general types of anxiety manifestations. This paper examines the possible causes of language anxiety in that a wider range of insights can be gained for effective foreign language teaching. A close review of the literature enables us to categorize language anxiety as learner-induced, classroom-related, skill-specific, and some culture-imposed, depending on different contexts. The potential sources provide us with an insightful view in the understanding of the difficulties students may have encountered in their process of language learning.

Summary Interferon regulatory factor 3 (IRF3) is a critical transcription factor for inducing production of type I interferons (IFN‐I) and regulating host antiviral response. Although IRF3 activation during viral infection has been extensively studied, the inhibitory regulation of IRF3 remains largely unexplored. Here, we revealed that Midline‐1 (MID1) is a ubiquitin E3 ligase of IRF3 that plays essential roles in regulating the production of IFN‐I. We found that MID1 physically interacts with IRF3 and downregulates IRF3 protein levels. Next, we demonstrated that MID1 can induce K48‐linked polyubiquitination of IRF3, thus lowing the protein stability of IRF3. Our further studies identified Lys313 as a major ubiquitin acceptor lysine of IRF3 induced by MID1. Finally, MID1‐mediated ubiquitination and degradation of IRF3 restrict IFN‐I production and cellular antiviral response. This study uncovers a role of MID1 in regulating innate antiviral immunity and may provide a potential target for enhancing host antiviral activity.

NFAT1 is known for its roles in T cell development and activation. So far, the phosphorylation of NFAT1 has been extensively studied, but the other post‐translational modifications of NFAT1 remain largely unknown. In this study, we reported that NFAT1 is a linearly ubiquitinated substrate of linear ubiquitin chain assembly complex (LUBAC). LUBAC promoted NFAT1 linear ubiquitination, which in turn inhibited K48‐linked polyubiquitination of NFAT1 and therefore increased NFAT1 protein stability. Interestingly, the linear ubiquitination levels of NFAT1 in patients with the Kawasaki disease were upregulated. Further studies demonstrated that the patients with the Kawasaki disease had increased mRNA levels of HOIL‐1L. These findings revealed a linearly ubiquitinated substrate of LUBAC and an important biological function of NFAT1 linear ubiquitination in the Kawasaki disease and therefore may provide a novel strategy for the treatment of the Kawasaki disease.

Type I IFN (IFN‐I) is the body's first line of defense against pathogen infection. IFN‐I can induce cellular antiviral responses and therefore plays a key role in driving antiviral innate and adaptive immunity. Canonical IFN‐I signaling activates the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, which induces the expression of IFN‐stimulated genes and eventually establishes a complex antiviral state in the cells. Ubiquitin is a ubiquitous cellular molecule for protein modifications, and the ubiquitination modifications of protein have been recognized as one of the key modifications that regulate protein levels and/or signaling activation. Despite great advances in understanding the ubiquitination regulation of many signaling pathways, the mechanisms by which protein ubiquitination regulates IFN‐I‐induced antiviral signaling have not been explored until very recently. This review details the current understanding of the regulatory network of ubiquitination that critically controls the IFN‐I‐induced antiviral signaling pathway from three main levels, including IFN‐I receptors, IFN‐I‐induced cascade signals, and effector IFN‐stimulated genes.

Type I interferon (IFN‐I) is a common biological molecule used for the treatment of viral diseases. However, the clinical antiviral efficacy of IFN‐I needs to be greatly improved. In this study, IFN‐I receptor 2 (IFNAR2) was revealed to undergo degradation at the protein level in cells treated with IFN‐I for long periods of time. Further studies found a physical interaction between the E3 ubiquitin ligase midline‐1 (MID1) and IFNAR2. As a consequence, MID1 induced both K48‐ and K63‐linked polyubiquitination of IFNAR2, which promoted IFNAR2 protein degradation in a lysosome‐dependent manner. Conversely, knockdown of MID1 largely restricted IFN‐I‐induced degradation of IFNAR2. Importantly, MID1 regulated the strength of IFN‐I signalling and IFN‐I‐induced antiviral activity. These findings reveal a regulatory mechanism of IFNAR2 ubiquitination and protein stability in IFN‐I signalling, which could provide a potential target for improving the antiviral efficacy of IFN‐I.