title: Quantitative nuclear proteomics reveals new phenotypes altered in lymphoblastoid cells.
abstract: B-lymphocytes are essential for the production of antibodies to fight pathogens and are the cells of origin in 95% of human lymphomas. During their activation, and immortalisation by Epstein-Barr virus (EBV) which contributes to human cancers, B-lymphocytes undergo dramatic changes in cell size and protein content. This study was initiated to compare the proteome of two B-cell lines, from the same individual, that reflect different patterns of activation, one is EBV negative and the other is EBV positive. Using isobaric tags, LC-MALDI TOF-TOF and subcellular fractionation, we quantified 499 proteins from B-cells. From a detergent lysed protein extract, we identified 34 proteins that were differentially expressed in EBV-immortalised B-cells. By analysing a nuclear extract, we identified a further 29 differentially expressed proteins with only four proteins shared between the two extracts, illustrating the benefit of subcellular fractionation. This analysis has identified proteins involved in the cytoskeletal phenotype of activated B-cells and the increased antigen recognition in EBV-immortalised cells. Importantly, we have also identified new regulators of transcription and changes in ribonuclear proteins that may contribute to the increased cell size and immortalisation of lymphoblastoid cells.
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, UK. brennanp@cardiff.ac.uk.
authors.forename: Paul
authors.initials: P
authors.lastname: Brennan
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Angharad M
authors.initials: AM
authors.lastname: Shore
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Mathew
authors.initials: M
authors.lastname: Clement
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Saman
authors.initials: S
authors.lastname: Hewamana
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Catrin M
authors.initials: CM
authors.lastname: Jones
authors.affiliation: Department of Pathology, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Giles
authors.affiliation: Department of Haematology, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Fegan
authors.affiliation: Department of Haematology, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Pepper
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Brewis
keywords: B‐cell; Coronin 1A; Epstein–Barr virus; Transcription factor