Intracellular distribution of human T-cell leukemia virus type 1 Gag proteins is independent of interaction with intracellular membranes.
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.
Le Blanc
Isabelle
I
INSERM U332, Service de Cytofluorométrie, ICGM. CNRS UMR 144, Institut Curie, Paris, France. Isabelle.LeBlanc@biochem.unige.ch
Blot
Vincent
V
Bouchaert
Isabelle
I
Salamero
Jean
J
Goud
Bruno
B
Rosenberg
Arielle R
AR
Dokhélar
Marie-Christine
MC
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
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