Structure and function correlation in histone H2A peptide-mediated gene transfer

^*Departments of Molecular and Experimental Medicine and ^‡Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, MEM 215, La Jolla, CA, 92037; and ^¶Genetic Therapy Inc., 9 West Watkins Mill Road, Gaithersburg, MD 20878

Contributed by Ernest Beutler

Abstract

Histone H2A has been found to be efficient in DNA delivery into a number of cell lines. We have reasoned that this DNA-delivery activity is mediated by two mechanisms: (i) electrostatically driven DNA binding and condensation by histone and (ii) nuclear import of these histone H2A⋅DNA polyplexes via nuclear localization signals in the protein. We have identified a 37-aa N-terminal peptide of histone H2A that is active in in vitro gene transfer. This peptide can function as a nuclear localization signal and can bind DNA. Amino acid substitutions that replace positively charged residues and/or DNA-binding residues of this peptide obliterate transfection activity. The introduction of a proline in the first turn of an α-helix of this 37-mer obliterates transfection activity, suggesting that the integrity of the α-helical structure of the N-terminal region of histone H2A is related to its transfection activity.

transfection‖nuclear localization signal‖DNA binding

Footnotes

↵ † Present address: Department of Medicine, Centre Hospitalier de l'Université de Montréal Hôtel-Dieu, Pavillon Masson, 3850, rue Saint-Urbain, Montréal, QC, Canada H2W 1T7.
↵ § Present address: The Ludwig Institute for Cancer Research, 9500 Gilman Drive, CMME 3080, La Jolla, CA 92093.
↵ ‖ Present address: Intradigm Corporation, 12115K Parklawn Drive, Rockville, MD 20852.
Abbreviation:

CMV,

cytomegalovirus