In mammalian cells, distinct H3K4 methylation states are created by deposition of methyl groups by multiple complexes of histone lysine methyltransferase 2 (KMT2) family proteins. For comprehensive analyses that directly compare the catalytic properties of all six human KMT2 complexes, we employed a biochemically defined system reconstituted with recombinant KMT2 core complexes (KMT2CoreCs) containing minimal components required for nucleosomal H3K4 methylation activity. We found that each KMT2CoreC generates distinct states and different levels of H3K4 methylation, and except for MLL3 all are stimulated by H2Bub. Notably, SET1BCoreC exhibited the strongest H3K4 methylation activity and, to our surprise, did not require H2B ubiquitylation (H2Bub); in contrast, H2Bub was required for the H3K4me2/3 activity of the paralog SET1ACoreC. We also found that WDR5, RbBP5, ASH2L and DPY30 are required for efficient H3K4 methyltransferase activities of all KMT2CoreCs except MLL3, which could produce H3K4me1 in the absence of WDR5. Importantly, deletion of the PHD2 domain of CFP1 led to complete loss of the H3K4me2/3 activities of SET1A/BCoreCs in the presence of H2Bub, indicating a critical role for this domain in the H2Bub-stimulated H3K4 methylation. Collectively, our results suggest that each KMT2 complex methylates H3K4 through distinct mechanisms in which individual subunits differentially participate.

Dynamic changes in chromatin structure are crucial for diverse biological processes. Given the complexity of the epigenetic landscape, understanding the specificity of chromatin modification has been a major interest in the epigenetics field. Recent progress in biochemical and structural analyses in the field of chromatin biology has revealed that recognition of allosteric effectors and the subsequent conformational change(s) are central to the regulation of catalytic activities and functions of chromatin-modifying enzymes. Here, we review several examples of distinctive nucleosome features, including DNA methylation, histone modifications, and variable-length linker DNA, that allosterically regulate the enzymatic activities of chromatin modifiers to confer functional specificity in a given chromatin context. We further highlight the biological significance of these allosteric mechanisms and discuss their potential as emerging targets for selective modulation of chromatin architecture.

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Sports careers are an interesting field for adolescents who enjoy participating in sports. Sports career education provides special support to learners by educating them about occupational sustainability and even discontinuation possibilities. Most sports career education programs implemented in schools and other institutions are unsystematic and ineffective. That is, the lack of systematic guidance by educators or counselors at schools make promising adolescents with talents and/or interests in sports look for different career paths. This study developed the best content standards in sports career education for adolescents using a Delphi survey from Korean professional views. The Delphi survey included three rounds and was conducted with 20 professionals from the field. Five content domains and 30 sub-content elements were identified as the best content standards in sports. Based on the consensus, the five content domains identified were as follows: (a) understanding sports careers, (b) self-understanding in sports, (c) understanding sports-related occupations, (d) exploring sports careers, and (e) designing sports careers. The best content standards identified in this study provided important data regarding the educational resources that educators or counselors could use to assist adolescents who enjoy playing sports or who consider sports as their future career path. These standards could guide the decision-making of educators or counselors regarding the best educational content and activities for sports careers. Furthermore, these standards could play a significant role in discovering and nurturing the needs and aptitudes of a diverse group of adolescents in sports.

This study aims to discuss sustainable re-education of physical education teachers by deriving the types of self-development through novice physical education teachers’ experiences of teacher learning community activities. A qualitative research method was used with six physical education teachers from six middle schools located in the Seoul metropolitan area (Seoul, Gyeonggi, and Incheon) in Korea, from which the following types of self-development were obtained: The first category of self-development is “to copy.” They accept everything as new and follow along. The second category is “to critique.” They compare, analyze and criticize each other’s classes with their community members. The third category is “to share.” They proactively share their ideas to transform “what is mine” into “what is ours.” The fourth category is “to create.” They build a new community that is suitable for them and create a process of giving and receiving help. In conclusion, we emphasized that teacher community learning activities of novice physical education teachers in Korea can provide an environment for the re-education of teachers that supports not only continuous self-development but also continuous professional development. As a follow-up study, we suggest a longitudinal study that will enable the understanding of physical education teachers’ continuous teacher learning community activities based on their stage of career growth as teachers. It will include a study on the continuity of re-education of physical education teachers according to the size of a teacher learning community or the relationships between members.