1. Mutagenesis of phospholipase D defines a superfamily including a trans-Golgi viral protein required for poxvirus pathogenicity.
- Author
-
Tsung-Chang Sung, Roper, Rachel L., Yue Zhang, Rudge, Simon A., Temel, Ryan, Hammond, Scott M., Morris, Andrew J., Moss, Bernard, Engebrecht, JoAnne, and Frohman, Michael A.
- Subjects
- *
PHOSPHOLIPASES , *GENES , *MUTAGENESIS , *VIRAL proteins , *ORGANELLES , *VIRUS diseases , *GENETIC mutation , *MICROBIAL genetics - Abstract
Phospholipase D (PLD) genes are members of a superfamily that is defined by several highly conserved motifs. PLD in mammals has been proposed to play a role in membrane vesicular trafficking and signal transduction. Using site-directed mutagenesis, 25 point mutants have been made in human PLD1 (hPLD1) and characterized. We find that a motif (HxKxxxxD) and a serine/threonine conserved in all members of the PLD superfamily are critical for PLD biochemical activity, suggesting a possible catalytic mechanism. Functional analysis of catalytically inactive point mutants for yeast PLD demonstrates that the meiotic phenotype ensuing from PLD deficiency in yeast derives from a loss of enzymatic activity. Finally, mutation of an HxKxxxxD motif found in a vaccinia viral protein expressed in the Golgi complex results in loss of efficient vaccinia virus cell-to-cell spreading, implicating the viral protein as a member of the superfamily and suggesting that it encodes a lipid modifying or binding activity. The results suggest that vaccinia virus and hPLD1 may act through analogous mechanisms to effect viral cellular egress and vesicular trafficking, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 1997
- Full Text
- View/download PDF