title: Intracellular distribution of human T-cell leukemia virus type 1 Gag proteins is independent of interaction with intracellular membranes.
abstract: Retrovirus Gag proteins are synthesized on free ribosomes, and are sufficient to govern the assembly and release of virus particles. Like type C retroviruses, human T-cell leukemia virus type 1 (HTLV-1) assembles and buds at the plasma membrane. After immunofluorescence staining, HTLV-1 Gag proteins appear as punctuated intracellular clusters, which suggests that they are associated either with intracellular membranes or with the plasma membrane. However, colocalization experiments using a panel of markers demonstrated that Gag proteins were not associated with the membranes involved in the secretory or endocytosis pathway. Small amounts of Gag proteins were detected at the plasma membrane and colocalized with the envelope glycoproteins. Moreover, Gag proteins were excluded from streptolysin-O permeabilized cells and in this respect behaved like cytoplasmic proteins. This suggests that the trafficking of HTLV-1 Gag proteins through the cytoplasm of the host cell is independent of any cell membrane system.
authors.affiliation: INSERM U332, Service de Cytofluorométrie, ICGM. CNRS UMR 144, Institut Curie, Paris, France. Isabelle.LeBlanc@biochem.unige.ch
authors.forename: Isabelle
authors.initials: I
authors.lastname: Le Blanc
authors.forename: Vincent
authors.initials: V
authors.lastname: Blot
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bouchaert
authors.forename: Jean
authors.initials: J
authors.lastname: Salamero
authors.forename: Bruno
authors.initials: B
authors.lastname: Goud
authors.forename: Arielle R
authors.initials: AR
authors.lastname: Rosenberg
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Dokhélar
mesh_terms: D000199:Actins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism / Q000821:virology; D002463:Cell Membrane Permeability / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism / Q000821:virology; D015683:Gene Products, gag / Q000032:analysis / Q000378:metabolism*; D015368:Human T-lymphotropic virus 1 / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism* / Q000821:virology; D008562:Membrane Glycoproteins / Q000378:metabolism; D021381:Protein Transport; D015682:Retroviridae Proteins, Oncogenic / Q000032:analysis / Q000378:metabolism*; D013301:Streptolysins / Q000494:pharmacology; D054301:gag Gene Products, Human Immunodeficiency Virus
chemical_list: D000199:Actins; D015683:Gene Products, gag; D008562:Membrane Glycoproteins; D015682:Retroviridae Proteins, Oncogenic; D013301:Streptolysins; D054301:gag Gene Products, Human Immunodeficiency Virus; C060955:p19 protein, Human T-lymphotropic virus 1