pDsRed-Express2-N1

pDsRed-Express2-N1 is a mammalian expression vector designed to express a protein of interest fused to the N-terminus of DsRed-Express2, a variant of the Discosoma sp. red fluorescent protein, DsRed (1). DsRed-Express2 retains the fast maturation and high photostability characteristic of its predecessor, DsRed-Express (2), and has been engineered (through additional amino acid substitutions) for increased solubility (3). Although it most likely forms the same tetrameric structure as wild-type DsRed, DsRed-Express2 displays a greatly reduced tendency to aggregate, resulting in reduced cyto- and phototoxicity, and making DsRed-Express2 much better suited for in vivo applications involving sensitive cells, such as primary or stem cells. (Please note: Because DsRed-Express2 likely forms tetramers, its suitability as a fusion partner will largely depend on how its tetramerization affects the function of the protein to which it is fused.) DsRed-Express2 also exhibits extremely low residual green fluorescence, which allows cells expressing the protein to be effectively separated from other fluorescently labeled cell populations by flow cytometry. The multiple cloning site (MCS) in pDsRed-Express2-N1 is positioned upstream of the DsRed-Express2 coding sequence. A Kozak consensus sequence (4), located between the MCS and the DsRed-Express2 coding sequence, enhances the translational efficiency of the unfused DsRed-Express2 protein in eukaryotic cells. SV40 polyadenylation signals downstream of the DsRed-Express2 coding sequence direct proper processing of the 3' ends of the DsRed-Express2 and fusion gene mRNA transcripts.