Improved intracellular delivery of glucocerebrosidase mediated by the HIV-1 TAT protein transduction domain.

Abstract

Enzyme replacement therapy (ERT) for Gaucher disease designed to target glucocerebrosidase (GC) to macrophages via mannose-specific endocytosis is very effective in reversing hepatosplenomegaly, and normalizing hematologic parameters but is less effective in improving bone and lung involvement and ineffective in brain. Recombinant GCs containing an in-frame fusion to the HIV-1 trans-activator protein transduction domain (TAT) were expressed in eukaryotic cells in order to obtain active, normally glycosylated GC fusion proteins for enzyme uptake studies. Despite the absence of mannose-specific endocytic receptors on the plasma membranes of various fibroblasts, the recombinant GCs with C-terminal TAT fusions were readily internalized by these cells. Immunofluorescent confocal microscopy demonstrated the recombinant TAT-fusion proteins with a mixed endosomal and lysosomal localization. Thus, TAT-modified GCs represent a novel strategy for a new generation of therapeutic enzymes for ERT for Gaucher disease.

• Authors: Kyun Oh Lee, Nga Luu, Christine R Kaneski, Raphael Schiffmann, Roscoe O Brady, Gary J Murray
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 337 Issue 2 Pg. 701-7 (Nov 18 2005) ISSN: 0006-291X [Print] United States
• PMID: 16223608 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Gene Products, tat
• Recombinant Fusion Proteins
• tat Gene Products, Human Immunodeficiency Virus
• Glucosylceramidase

Topics

• Base Sequence
• Cell Membrane (metabolism)
• Cells, Cultured
• Endocytosis (drug effects, physiology)
• Eukaryotic Cells (drug effects, metabolism)
• Fibroblasts (cytology, drug effects, metabolism)
• Gene Products, tat (pharmacology)
• Glucosylceramidase (metabolism)
• HIV-1 (metabolism)
• Humans
• Microscopy, Confocal
• Protein Structure, Tertiary (physiology)
• Recombinant Fusion Proteins (metabolism)
• tat Gene Products, Human Immunodeficiency Virus