title: Protein degradation and apoptotic death in lymphocytes during Fiv infection: activation of the ubiquitin-proteasome proteolytic system.
abstract: The movement of a cell through the sequential phases of apoptosis is accompanied by a progressive decrease in cell size with loss in protein mass. In lymphocytes from Hiv-infected persons, protein loss during apoptosis is due to increased protein degradation rather than decreased synthesis. To identify and characterize the proteolytic enzymes or enzyme systems involved in this process, we studied several features of protein turnover in lymphocytes from peripheral blood and lymph nodes during the natural and experimental infection by feline immunodeficiency virus (Fiv). This animal model allowed us to integrate in vivo results with in vitro observations of protein damage. Here we report that protein breakdown in apoptotic cells is concomitant with the activation of the ATP and ubiquitin-dependent multicatalytic system (proteasome). We suggest that proteasome activation is part of the proteolytic cascade in the execution phases of apoptosis in AIDS.
authors.affiliation: Facoltà di Medicina Veterinaria, Università di Messina, Messina, 98123, Italy. piedimon@imeuniv.unime.it
authors.forename: G
authors.initials: G
authors.lastname: Piedimonte
authors.forename: R
authors.initials: R
authors.lastname: Crinelli
authors.forename: L
authors.initials: L
authors.lastname: Della  Salda
authors.forename: D
authors.initials: D
authors.lastname: Corsi
authors.forename: M G
authors.initials: MG
authors.lastname: Pennisi
authors.forename: L
authors.initials: L
authors.lastname: Kramer
authors.forename: A
authors.initials: A
authors.lastname: Casabianca
authors.forename: G
authors.initials: G
authors.lastname: Sarli
authors.forename: M
authors.initials: M
authors.lastname: Bendinelli
authors.forename: P S
authors.initials: PS
authors.lastname: Marcato
authors.forename: M
authors.initials: M
authors.lastname: Magnani
mesh_terms: D000818:Animals; D017209:Apoptosis; D002415:Cats; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D005260:Female; D006207:Half-Life; D016089:Immunodeficiency Virus, Feline / Q000254:growth & development*; D016180:Lentivirus Infections / Q000378:metabolism*; D008198:Lymph Nodes / Q000378:metabolism* / Q000473:pathology; D008214:Lymphocytes / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000378:metabolism; D014452:Ubiquitins / Q000378:metabolism*
chemical_list: D009097:Multienzyme Complexes; D011506:Proteins; D014452:Ubiquitins; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex