Open AccessZ-membranes: artificial organelles for overexpressing recombinant integral membrane proteins.
Author(s) -
Fangcheng Gong,
T. H. Giddings,
Janet B. Meehl,
L. Andrew Staehelin,
David W. Galbraith
Publication year - 1996
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.93.5.2219
Subject(s) - endoplasmic reticulum , membrane , integral membrane protein , organelle , membrane protein , biology , microbiology and biotechnology , fusion protein , recombinant dna , biochemistry , gene
We have expressed a fusion protein formed between the avian infectious bronchitis virus M protein and the bacterial enzyme beta-glucuronidase in transgenic tobacco cells. Electron microscope images of such cells demonstrate that overexpression of this fusion protein gives rise to a type of endoplasmic reticulum membrane domain in which adjacent membranes become zippered together apparently as a consequence of the oligomerizing action of beta-glucuronidase. These zippered (Z-) membranes lack markers of the endoplasmic reticulum (NADH cytochrome c reductase and ribosomes) and accumulate in the cells in the form of multilayered scroll-like structures (up to 2 micrometers in diameter; 20-50 per cell) without affecting plant growth. The discovery of Z-membranes has broad implications for biology and biotechnology in that they provide a means for accumulating large quantities of recombinant membrane proteins within discrete domains of native membranes.