{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nSCMH1, a mammalian homolog of Drosophila Sex comb on midleg, functions as an integral component of Polycomb repressive complex 1 (PRC1) during key developmental stages. In male germ cells undergoing meiotic prophase, SCMH1 is essential for mediating sequential chromatin modifications, especially through its exclusion from the XY body at late pachytene. Loss of SCMH1 leads to defects in these chromatin transitions and the apoptotic elimination of spermatocytes, underscoring its regulatory role in maintaining proper gene repression during meiosis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn hematopoietic cells, SCMH1 is also critical for transcriptional silencing mediated by PRC1. Here, its interaction with geminin supports the maintenance of homeostatic gene expression, as seen by the derepression of key Hox genes such as Hoxb4 and Hoxa9 in its absence. Through the formation of E3 ubiquitin ligase complexes with these transcription factors, SCMH1 contributes indirectly to geminin stability, revealing a tight regulatory circuit that balances protein turnover and transcriptional control."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nAlthough distinct from SCMH1’s roles in chromatin and transcription regulation, proper cell division requires the coordinated function of multiple factors such as the centrosomal protein CENP-32. Depletion of CENP-32 results in the release of centrosomes from the spindle apparatus, yet the assembly of a functional anastral spindle permits accurate chromosome alignment and segregation. This study underscores the complexity of intracellular machinery ensuring faithful mitosis, reminding us that while SCMH1 and PRC1 maintain epigenetic integrity, other proteins guarantee the correct physical partitioning of chromosomes."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn addition to its roles in development and cell cycle regulation, SCMH1 is also linked to pathological conditions through its circular RNA isoform, circSCMH1. In the context of diabetic retinopathy, elevated levels of circSCMH1 contribute to epithelial-mesenchymal transition (EMT) in retinal pigment epithelial cells by modulating the miR-200a-3p/ZEB1 axis. Downregulation of circSCMH1 rescues these cellular alterations, suggesting that targeted modulation of the circRNA may offer novel therapeutic opportunities to mitigate EMT and subsequent retinal damage in diabetes."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Yuki Takada, Kyo-ichi Isono, Jun Shinga, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Mammalian Polycomb Scmh1 mediates exclusion of Polycomb complexes from the XY body in the pachytene spermatocytes."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Development (2007)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1242/dev.02747"}], "href": "https://doi.org/10.1242/dev.02747"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "17215307"}], "href": "https://pubmed.ncbi.nlm.nih.gov/17215307"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Shin'ichiro Yasunaga, Motoaki Ohtsubo, Yoshinori Ohno, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Scmh1 has E3 ubiquitin ligase activity for geminin and histone H2A and regulates geminin stability directly or indirectly via transcriptional repression of Hoxa9 and Hoxb4."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell Biol (2013)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1128/MCB.00974-12"}], "href": "https://doi.org/10.1128/MCB.00974-12"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "23207902"}], "href": "https://pubmed.ncbi.nlm.nih.gov/23207902"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Shinya Ohta, Laura Wood, Iyo Toramoto, et al. "}, {"type": "b", "children": [{"type": "t", "text": "CENP-32 is required to maintain centrosomal dominance in bipolar spindle assembly."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Biol Cell (2015)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1091/mbc.E14-09-1366"}], "href": "https://doi.org/10.1091/mbc.E14-09-1366"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25657325"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25657325"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Ye He, Xiang-Tao Hou, Yu-Xin Guan, et al. "}, {"type": "b", "children": [{"type": "t", "text": "CircRNA SCMH1 regulates the miR-200a-3p/ZEB1 signaling axis to promote diabetes-induced retinal epithelial-mesenchymal transition."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Exp Eye Res (2022)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.exer.2022.109264"}], "href": "https://doi.org/10.1016/j.exer.2022.109264"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "36162459"}], "href": "https://pubmed.ncbi.nlm.nih.gov/36162459"}]}]}]}