Abstract
Herpes simplex virus serotype 1 (HSV-1) expresses an immediate-early protein, ICP47, that effectively blocks the major histocompatibility complex class I antigen presentation pathway. HSV-1 ICP47 (ICP47-1) binds with high affinity to the human transporter associated with antigen presentation (TAP) and blocks the binding of antigenic peptides. HSV type 2 (HSV-2) ICP47 (ICP47-2) has only 42% amino acid sequence identity with ICP47-1. Here, we compared the levels of inhibition of human and murine TAP, expressed in insect cell microsomes, by ICP47-1 and ICP47-2. Both proteins inhibited human TAP at similar concentrations, and the K(D) for ICP47-2 binding to human TAP was 4.8 x 10-8 M, virtually identical to that measured for ICP47-1 (5.2 x 10-8 M). There was some inhibition of murine TAP by both ICP47-2 and ICP47- 1, but this inhibition was incomplete and only at ICP47 concentrations 50 to 100 times that required to inhibit human TAP. Lack of inhibition of murine TAP by ICP47-1 and ICP47-2 could be explained by an inability of both proteins to bind to murine TAP.
Original language | English (US) |
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Pages (from-to) | 2560-2563 |
Number of pages | 4 |
Journal | Journal of virology |
Volume | 72 |
Issue number | 3 |
DOIs | |
State | Published - 1998 |
ASJC Scopus subject areas
- Microbiology
- Immunology
- Insect Science
- Virology