International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Mr. Daewoong Jo
Vanderbilt University
AA4206, 1161 21st Ave South
Nashville, TN
37211
USA

Co-Authors: Nashabi A., Lin Q., Chen J., Doxsee C., May D., Unutmaz D, Pietenpol J, Ruley HE
Institutions: Department of Microbiology and Immunology, Vanderbilt University School of Medicine

Studies of mammalian gene function are hampered by temporal limitations in which phenotypes occurring at one stage of development interfere with analysis at later stages.  Moreover, phenotypes resulting from altered gene activity include both direct and indirect effects that may be difficult to distinguish. In the present study, recombinant fusion proteins bearing the 12 amino acid membrane translocation sequence (MTS) from the Kaposi Fibroblast Growth Factor  were used to transduce enzymatically active Cre proteins directly into mammalian cells. High levels of recombination were observed in a variety of cultured cell types and in all tissues examined in mice following intraperitoneal administration.  The rate of recombination in cultured cells was also found to vary according to cell cycle.  As protein uptake did not appear to be affected by cell cycle stage, the differences in recombination rates may reflect differences in chromatin accessibility.  This represents the first use of protein transduction to induce the enzymatic conversion of a substrate in living cells and animals, and provides a rapid and efficient means to manipulate mammalian gene structure and function. Moreover, the studies using Cre illustrate advantages of protein transduction over conventional gene-based approaches to quantify the direct effects of an enzyme on biochemical and biological processes in living cells under non steady-state conditions.