IBMPFD/ALS is a genetic disorder caused by a single amino acid mutation on the p97 ATPase, promoting ATPase activity and cofactor dysregulation. The disease mechanism underlying p97 ATPase malfunction remains unclear. To understand how the mutation alters the ATPase regulation, we assembled a full-length p97^R155H with its p47 cofactor and first visualized their structures using single-particle cryo-EM. More than one-third of the population was the dodecameric form. Nucleotide presence dissociates the dodecamer into two hexamers for its highly elevated function. The N-domains of the p97^R155H mutant all show up configurations in ADP- or ATPγS-bound states. Our functional and structural analyses showed that the p47 binding is likely to impact the p97^R155H ATPase activities via changing the conformations of arginine fingers. These functional and structural analyses underline the ATPase dysregulation with the miscommunication between the functional modules of the p97^R155H.

Valosin-containing protein (VCP) gene mutations have been associated with a rare autosomal dominant, adult-onset progressive disease known as multisystem proteinopathy 1 (MSP1), or inclusion body myopathy (IBM), Paget’s disease of bone (PDB), frontotemporal dementia (FTD), (IBMPFD), and amyotrophic lateral sclerosis (ALS). We report the clinical and genetic analysis findings in five patients, three from the same family, with novel VCP gene variants: NM_007126.5 c.1106T>C (p.I369T), c.478G>A (p.A160T), and c.760A>T (p.I254F), associated with cardinal MSP1 manifestations including myopathy, PDB, and FTD. Our report adds to the spectrum of heterozygous pathogenic variants found in the VCP gene and the high degree of clinical heterogeneity. This case series prompts increased awareness and early consideration of MSP1 in the differential diagnosis of myopathies and/or PDB, dementia, or ALS to improve the diagnosis and early management of clinical symptoms.

Background: Variants in the mitochondrial complex I assembly factor, NUBPL are associated with a rare cause of complex I deficiency mitochondrial disease. Patients affected by complex I deficiency harboring homozygous NUBPL variants typically have neurological problems including seizures, intellectual disability, and ataxia associated with cerebellar hypoplasia. Thus far only 19 cases have been reported worldwide, and no treatment is available for this rare disease. Methods: To investigate the pathogenesis of NUBPL-associated complex I deficiency, and for translational studies, we generated a knock-in mouse harboring a patient-specific variant Nubpl c.311T>C; p. L104P reported in three families. Results: Similar to Nubpl global knockout mice, the Nubpl p. L104P homozygous mice are lethal at embryonic day E10.5, suggesting that the Nubpl p. L104P variant is likely a hypomorph allele. Given the recent link between Parkinson’s disease and loss-of-function NUBPL variants, we also explored aging-related behaviors and immunocytochemical changes in Nubpl hemizygous mice and did not find significant behavioral and pathological changes for alpha-synuclein and oxidative stress markers . Conclusion: Our data suggest that homozygotes with Nubpl variants, similar to the null mice, are lethal, and heterozygotes are phenotypically and neuropathologically normal. We propose that a tissue-specific knockout strategy is required to establish a mouse model of Nubpl-associated complex I deficiency disorder for future mechanistic and translational studies.

P97 protein is a highly conserved, abundant, functionally diverse, structurally dynamic homohexameric AAA enzyme-containing N, D1, and D2 domains. A truncated p97 protein containing the N and D1 domains and the D1-D2 linker (ND1L) exhibits 79% of wild-type (WT) ATPase activity whereas the ND1 domain alone without the linker only has 2% of WT activity. To investigate the relationship between the D1-D2 linker and the D1 domain, we produced p97 ND1L mutants and demonstrated that this 22-residue linker region is essential for D1 ATPase activity. The conserved amino acid leucine 464 (L464) is critical for regulating D1 and D2 ATPase activity by p97 cofactors p37, p47, and Npl4-Ufd1 (NU). Changing leucine to alanine, proline, or glutamate increased the maximum rate of ATP turnover (k_cat) of p47-regulated ATPase activities for these mutants, but not for WT. p37 and p47 increased the k_cat of the proline substituted linker, suggesting that they induced linker conformations facilitating ATP hydrolysis. NU inhibited D1 ATPase activities of WT and mutant ND1L proteins, but activated D2 ATPase activity of full-length p97. To further understand the mutant mechanism, we used single-particle cryo-EM to visualize the full-length p97^L464P and revealed the conformational change of the D1-D2 linker, resulting in a movement of the helix-turn-helix motif (543-569). Taken together with the biochemical and structural results we conclude that the linker helps maintain D1 in a competent conformation and relays the communication to/from the N-domain to the D1 and D2 ATPase domains, which are ~50 Å away.

Alterations in mRNA splicing play a critical role in driving the molecular heterogeneity of many cancers, including urothelial carcinoma, by contributing to disease progression, treatment response, and clinical outcomes. These splicing changes can arise from somatic mutations in core spliceosomal components or through alternative splicing events affecting cancer-associated genes. In this review, we examine how dysregulation of pre-mRNA splicing influences key aspects of urothelial carcinoma biology, including cell proliferation, invasion, metastasis, modulation of the immune microenvironment, metabolism, and therapeutic resistance. We highlight frequently observed splicing-factor mutations and discuss the impact of aberrant splicing and cancer-specific isoforms on prognosis. We also explore splicing alterations associated with susceptibility to urothelial carcinoma and review emerging therapeutic strategies, such as splice-switching oligonucleotides and small molecule spliceosome inhibitors, that offer promising avenues for precision medicine in this disease.

PURPOSE: Southeast Asia (SEA), home to over 690 million people across 11 countries—Brunei, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, the Philippines, Singapore, Thailand, Timor-Leste, and Vietnam—features diverse socioeconomic contexts and cancer care landscapes. We report and interpret incidence and mortality statistics for hematologic malignancies (HMs) in SEA. METHODS: We analyzed 2022 Global Cancer Observatory data from the International Agency for Research on Cancer to report age-standardized incidence rate (ASIR) and age-standardized mortality rates (ASMR) per 100,000 individuals age 20 years and older. We focused on non-Hodgkin lymphoma (NHL), leukemia, multiple myeloma (MM), and Hodgkin lymphoma (HL), standardized using Segi-Doll world population estimates. RESULTS: Across 11 Southeast Asian countries, age-standardized incidence and mortality rates (ASIRs and ASMRs) for HMs vary widely, highlighting significant regional disparities. Singapore consistently reports the highest ASIRs for NHL, leukemia, MM, and HL, yet its ASMRs are much lower, reflecting strong health care infrastructure. Thailand, Brunei, and Malaysia mirror these associations, which are particularly pronounced in NHL and HL. In contrast, for leukemia and MM, Brunei, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, the Philippines, Timor-Leste, and Vietnam demonstrated lower ASIR and ASMR that approaches ASIR, suggesting barriers to diagnosis and survivorship. Time trends suggest increasing mortality from MM and NHL, particularly in Thailand and the Philippines. Overall, survival outcomes correlate strongly with national health care capacity. CONCLUSION: Higher reported incidence in wealthier SEA countries may reflect greater diagnostic capacity, whereas similar incidence and mortality in low-income countries likely indicates limited access to timely diagnosis and treatment. Mortality patterns underscore the region's broad disparities in cancer care infrastructure and outcomes, shaped by socioeconomic and systemic health inequities.