{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nUBAP1 is a critical ubiquitin‐binding component of the endosomal sorting complex required for transport (ESCRT‐I) that plays a pivotal role in the recognition and sorting of ubiquitinated cargo. Studies have demonstrated that UBAP1 interacts selectively with specific ESCRT‐I partners—such as VPS37A and the tumor suppressor HD‑PTP—to mediate the efficient trafficking and degradation of cell surface receptors via the multivesicular body pathway. In neurons, genetic investigations have uncovered truncating mutations in UBAP1 that escape nonsense‑mediated decay, resulting in dominant‑negative forms that disrupt endosomal dynamics. These aberrations manifest as enlarged and clustered endosomes with a consequential accumulation of ubiquitinated proteins, thereby contributing to neurodegenerative conditions including hereditary spastic paraplegia (HSP) and frontotemporal lobar degeneration (FTLD)."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "7"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn addition to its involvement in neuronal homeostasis, UBAP1 appears to play a role in oncogenesis. Downregulation of UBAP1 has been observed in nasopharyngeal carcinoma, where its decreased expression may contribute to malignant transformation. Conversely, elevated levels of UBAP1 in acute leukemia—accompanied by an inverse correlation with the tumor suppressor p16—suggest that dysregulation of UBAP1 may influence cell cycle control and proliferation in certain hematologic malignancies."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "8"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n"}, {"type": "p", "children": [{"type": "t", "text": "\nMoreover, UBAP1 is targeted by pathogens to subvert host immune defenses. Specifically, a TIR domain–containing protein from multidrug‐resistant Pseudomonas aeruginosa has been shown to interact with UBAP1, along with key Toll‑like receptor (TLR) adaptors such as MyD88. This multifaceted interaction diminishes cytokine production and TLR receptor signaling, thereby illustrating a novel bacterial strategy for innate immune evasion."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "10"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Mohammad Ali Farazi Fard, Adriana P Rebelo, Elena Buglo, et al. 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