Host cell-virus cross talk: phosphorylation of a hepatitis B virus envelope protein mediates intracellular signaling.
J Virol
; 72(12): 10138-47, 1998 Dec.
Article
en En
| MEDLINE
| ID: mdl-9811754
ABSTRACT
Phosphorylation of cytosolic pre-S domains of the duck hepatitis B virus (DHBV) large envelope protein (L) was identified as a regulatory modification involved in intracellular signaling. By using biochemical and mass spectrometric analyses of phosphopeptides obtained from metabolically radiolabeled L protein, a single phosphorylation site was identified at serine 118 as part of a PX(S/T)P motif, which is strongly preferred by ERK-type mitogen-activated protein kinases (MAP kinases). ERK2 specifically phosphorylated L at serine 118 in vitro, and L phosphorylation was inhibited by a coexpressed MAP kinase-specific phosphatase. Furthermore, L phosphorylation and ERK activation were shown to be induced in parallel by various stimuli. Functional analysis with transfected cells showed that DHBV L possesses the ability to activate gene expression in trans and, by using mutations eliminating (S-->A) or mimicking (S-->D) serine phosphorylation, that this function correlates with L phosphorylation. These mutations had, however, no major effects on virus production in cell culture and in vivo, indicating that L phosphorylation and transactivation are not essential for hepadnavirus replication and morphogenesis. Together, these data suggest a role of the L protein in intracellular host-virus cross talk by varying the levels of pre-S phosphorylation in response to the state of the cell.
Texto completo:
1
Colección:
01-internacional
Asunto principal:
Proteínas Virales
/
Virus de la Hepatitis B del Pato
/
Proteínas del Envoltorio Viral
Límite:
Animals
Idioma:
En
Revista:
J Virol
Año:
1998
Tipo del documento:
Article
País de afiliación:
Alemania