Direct, Noncatalytic Mechanism of IKK Inhibition by A20

A20 is a potent anti-inflammatory protein that inhibits NF-κB, and A20 dysfunction is associated with autoimmunity and B-cell lymphoma. A20 harbors a deubiquitination enzyme domain and can employ multiple mechanisms to antagonize ubiquitination upstream of NEMO, a regulatory subunit of the IκB kinase complex (IKK). However, direct evidence of IKK inhibition by A20 is lacking, and the inhibitory mechanism remains poorly understood. Here we show that A20 can directly impair IKK activation without deubiquitination or impairment of ubiquitination enzymes. We find that polyubiquitin binding by A20, which is largely dependent on A20’s seventh zinc finger motif (ZnF7), induces specific binding to NEMO. Remarkably, this ubiquitin-induced recruitment of A20 to NEMO is sufficient to block IKK phosphorylation by its upstream kinase TAK1. Our results suggest a non-catalytic mechanism of IKK inhibition by A20 and a means by which polyubiquitin chains can specify a signaling outcome

An Experiential Learning-Based Virtual Reality Approach to Foster Students’ Vocabulary Acquisition and Learning Engagement in English for Geography

EFL learners encounter a number of challenges in English for specific purposes, especially in understanding and remembering vocabulary. Therefore, exploring effective ways to improve their vocabulary and its applications is the key area of ESP. VR, as a newer type of audiovisual input on incidental vocabulary learning, is an important tool for innovation in language education. With its sense of presence and immersion, VR constructs an experiential learning process for students involving incidental vocabulary acquisition to promote their learning engagement and performance. Therefore, this study applied an experiential learning-based VR approach to an English for Geography course in a university. Thirty-six geography students participated in vocabulary acquisition on the theme of the hydrologic cycle. For the experiment, 18 students were assigned to the experimental group learning with the VR-based approach, while the other 18 were assigned to the control group learning with the video-based approach. The findings demonstrated that the experimental group outperformed the control group in terms of incidental vocabulary acquisition and cognitive, behavioral, and social engagement