title: Cancer associated missense mutations in BAP1 catalytic domain induce amyloidogenic aggregation: A new insight in enzymatic inactivation.
abstract: BRCA1 associated protein 1 (BAP1) is a nuclear deubiquitinase that regulates tumor suppressor activity and widely involves many cellular processes ranging from cell cycle regulation to gluconeogenesis. Impairment of enzymatic activity and nuclear localization induce abnormal cell proliferation. It is considered to be an important driver gene, which undergoes frequent mutations in several cancers. However the role of mutation and oncogenic gain of function of BAP1 are poorly understood. Here, we investigated cellular localization, enzymatic activity and structural changes for four missense mutants of the catalytic domain of BAP1, which are prevalent in different types of cancer. These mutations triggered cytoplasmic/perinuclear accumulation in BAP1 deficient cells, which has been observed in proteins that undergo aggregation in cellular condition. Amyloidogenic activity of mutant BAP1 was revealed from its reactivity towards anti oligomeric antibody in HEK293T cells. We have also noted structural destabilization in the catalytic domain mutants, which eventually produced beta amyloid structure as indicated in atomic force microscopy study. The cancer associated mutants up-regulate heat shock response and activates transcription of genes normally co-repressed by BAP1. Overall, our results unambiguously demonstrate that structural destabilization and subsequent aggregation abrogate its cellular mechanism leading to adverse outcome.
authors.affiliation: Laboratory of Proteomics and Cellular Signaling, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad, Haryana 121001, INDIA.
authors.forename: Sushmita
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Laboratory of Proteomics and Cellular Signaling, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad, Haryana 121001, INDIA.|Department of Biotechnology, Manipal University, Karnataka, 576104, INDIA.
authors.forename: Pranita
authors.initials: P
authors.lastname: Hanpude
authors.affiliation: Laboratory of Proteomics and Cellular Signaling, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad, Haryana 121001, INDIA.
authors.forename: Tushar Kanti
authors.initials: TK
authors.lastname: Maiti
mesh_terms: D000682:Amyloid / Q000737:chemistry / Q000378:metabolism; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D057809:HEK293 Cells; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D020125:Mutation, Missense; D055550:Protein Stability; D017433:Protein Structure, Secondary; D025521:Tumor Suppressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D043222:Ubiquitin Thiolesterase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000682:Amyloid; C400134:BAP1 protein, human; D006360:Heat-Shock Proteins; D025521:Tumor Suppressor Proteins; D043222:Ubiquitin Thiolesterase