title: Proteomic analysis of the cell-surface membrane in chronic lymphocytic leukemia: identification of two novel proteins, BCNP1 and MIG2B.
abstract: B-cell-specific plasma-membrane proteins are potential targets for either small molecule or antibody-based therapies. We have sought to annotate proteins expressed at the cell surface membrane in patients with chronic lymphocytic leukemia (CLL) using plasma-membrane-based proteomic analysis to identify previously uncharacterized and potentially B-cell-specific proteins. Proteins from plasma-membrane fractions were separated on one-dimensional gels and trypsinized fractions subjected to high-throughput MALDI-TOF mass spectrometry. Using this method, many known B-cell surface antigens were detected, but also known proteins not previously described in this disease or in this cellular compartment, including cell surface receptors, membrane-associated enzymes and secreted proteins, and completely unknown proteins. To validate the method, we show that BLK, a B-cell-specific kinase, is located in the CLL-plasma-membrane fraction. We also describe two novel proteins (MIG2B and B-cell novel protein #1, BCNP1), which are expressed preferentially in B cells. MIG2B is in a highly conserved and defined gene family containing two plasma-membrane-binding ezrin/radixin/moesin domains and a pleckstrin homology domain; the Caenorhabditis elegans homolog (UNC-112) is a membrane-associated protein that colocalizes with integrin at cell-matrix adhesion complexes. BCNP1 is a completely unknown protein with three predicted transmembrane domains, with three alternatively spliced final exons. Proteomic analysis may thus define new potential therapeutic targets.
authors.affiliation: Oxford Glycosciences (UK) Ltd, Abingdon, Oxford, UK.
authors.forename: R S
authors.initials: RS
authors.lastname: Boyd
authors.forename: P J
authors.initials: PJ
authors.lastname: Adam
authors.forename: S
authors.initials: S
authors.lastname: Patel
authors.forename: J A
authors.initials: JA
authors.lastname: Loader
authors.forename: J
authors.initials: J
authors.lastname: Berry
authors.forename: N T
authors.initials: NT
authors.lastname: Redpath
authors.forename: H R
authors.initials: HR
authors.lastname: Poyser
authors.forename: G C
authors.initials: GC
authors.lastname: Fletcher
authors.forename: N A
authors.initials: NA
authors.lastname: Burgess
authors.forename: A C
authors.initials: AC
authors.lastname: Stamps
authors.forename: L
authors.initials: L
authors.lastname: Hudson
authors.forename: P
authors.initials: P
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Griffiths
authors.forename: T G
authors.initials: TG
authors.lastname: Willis
authors.forename: E L
authors.initials: EL
authors.lastname: Karran
authors.forename: D G
authors.initials: DG
authors.lastname: Oscier
authors.forename: D
authors.initials: D
authors.lastname: Catovsky
authors.forename: J A
authors.initials: JA
authors.lastname: Terrett
authors.forename: M J S
authors.initials: MJ
authors.lastname: Dyer
mesh_terms: D051017:Apoptosis Regulatory Proteins; D001402:B-Lymphocytes / Q000737:chemistry* / Q000473:pathology; D001483:Base Sequence; D015153:Blotting, Western; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D016366:Open Reading Frames; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D051017:Apoptosis Regulatory Proteins; C477322:FERMT3 protein, human; D008565:Membrane Proteins; C477321:NIBAN3 protein, human; D009363:Neoplasm Proteins; D020033:Protein Isoforms