{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nIn skeletal muscle, the BMP–Smad1/5/8 pathway plays a pivotal role in maintaining muscle mass by balancing protein synthesis and degradation. Within this framework, the expression of Fbxo30—an F‐box protein that functions as an E3 ubiquitin ligase—is negatively regulated by BMP signaling. Under conditions that favor muscle atrophy, the de-repression of Fbxo30 is implicated in ubiquitin‐mediated degradation processes, contributing indirectly to the regulation of proteins that facilitate muscle wasting."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn the context of oocyte maturation, Fbxo30 is highly enriched in mouse oocytes and then substantially downregulated after the first meiotic metaphase. Loss of Fbxo30 during meiotic progression results in abnormal chromosome compaction and segregation failure at the MI stage—a defect tied to impaired degradation of stem‐loop–binding protein (SLBP). The consequent SLBP overexpression leads to an overload of histone H3 on chromosomes, thereby excessively condensing them and impeding accurate chromosome segregation."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nFbxo30 also exerts a critical function in mammary gland development. It directly interacts with the bipolar spindle kinesin EG5 (encoded by Kif11), targeting EG5 for ubiquitination and thereby ensuring proper centriole homeostasis, mitotic spindle formation, and cell cycle progression in mammary epithelial cells. Disruption of this regulatory mechanism results in EG5 dysregulation, leading to defects in centrosome integrity and cell proliferation that culminate in impaired mammopoiesis—a phenotype that can be rescued by normalizing EG5 activity."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Roberta Sartori, Elija Schirwis, Bert Blaauw, et al. "}, {"type": "b", "children": [{"type": "t", "text": "BMP signaling controls muscle mass."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Nat Genet (2013)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/ng.2772"}], "href": "https://doi.org/10.1038/ng.2772"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24076600"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24076600"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Yimei Jin, Mo Yang, Chang Gao, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Fbxo30 regulates chromosome segregation of oocyte meiosis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cell Mol Life Sci (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1007/s00018-019-03038-z"}], "href": "https://doi.org/10.1007/s00018-019-03038-z"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "30980108"}], "href": "https://pubmed.ncbi.nlm.nih.gov/30980108"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Yan Liu, Yin Wang, Zhanwen Du, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Fbxo30 Regulates Mammopoiesis by Targeting the Bipolar Mitotic Kinesin Eg5."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cell Rep (2016)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.celrep.2016.03.083"}], "href": "https://doi.org/10.1016/j.celrep.2016.03.083"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "27117404"}], "href": "https://pubmed.ncbi.nlm.nih.gov/27117404"}]}]}]}