title: Cellular protein TIA-1 regulates the expression of HBV surface antigen by binding the HBV posttranscriptional regulatory element.
abstract: OBJECTIVE
  To identify T-cell intracellular antigen 1 (TIA-1) interacting with the posttranscriptional regulatory element (PRE) of hepatitis B virus (HBV), and reveal TIA-1 function on HBV gene expression.
  
  
  METHODS
  In order to demonstrate TIA-1 binding to PRE, electrophoretic mobility shift and RNA and protein pull-down assays were used. The pDM138-PRE reporter system, HepG2.2.15 cell line and HBs-PRE transient expression cells were adopted to identify TIA-1 function in the HBV life cycle.
  
  
  RESULTS
  TIA-1 could directly bind to PRE RNA. The functional binding region of TIA-1 was identified. Functional analysis indicated that TIA-1 could dose-dependently inhibit PRE function in pDM138-PRE system. Down-expression of HBs antigen induced by TIA-1 was detected both in the HepG2.2.15 cell line and in HBs-PRE transient expression cells.
  
  
  CONCLUSIONS
  These data demonstrated that TIA-1 inhibits HBs expression by interacting with PRE.
authors.affiliation: Key Laboratory of Molecular Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Tang
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Chao
authors.initials: C
authors.lastname: Yu
authors.forename: Ai-long
authors.initials: AL
authors.lastname: Huang