Use of plastid transit peptides derived from glaucocystophytes

Abstract

Compositions and methods for targeting polypeptides to plastids are provided. Compositions comprise plastid transit peptides as well as nucleotide sequences encoding such transit peptides and variants thereof. Compositions further comprise DNA constructs comprising a nucleotide sequence encoding the plastid transit peptide operably linked to a nucleotide sequence encoding a polypeptide of interest. These DNA constructs find use in expression and targeting of the polypeptide of interest to a plastid. Compositions also comprise expression cassettes, vectors, transformed plants, transformed plant cells, and stably transformed plant seeds wherein a polypeptide of interest is targeted to a plastid by the plastid transit peptide of the invention.

1 . An isolated nucleic acid comprising a first nucleotide sequence encoding a plastid transit peptide from a Glaucocystophyte wherein said first nucleotide sequence is operably linked to a second nucleotide sequence encoding a heterologous polypeptide. 
     
     
         2 . The isolated nucleic acid of  claim 1 , wherein the Glaucocystophyte is  Cyanophora.    
     
     
         3 . The isolated nucleic acid of  claim 1 , wherein the Glaucocystophyte is  Cyanophora paradoxa.    
     
     
         4 . The isolated nucleic acid of  claim 1 , wherein the plastid transit peptide is selected from the group consisting of SEQ ID NOs: 2, 3, 5 and 7. 
     
     
         5 . A transgenic plant comprising a first nucleotide sequence encoding a plastid transit peptide from a Glaucocystophyte wherein said first nucleotide sequence is operably linked to a second nucleotide sequence encoding a heterologous polypeptide, wherein said heterologous polypeptide is targeted to a chloroplast. 
     
     
         6 . The transgenic plant of  claim 5 , wherein the Glaucocystophyte is  Cyanophora.    
     
     
         7 . The transgenic plant of  claim 5 , wherein the Glaucocystophyte is  Cyanophora paradoxa.    
     
     
         8 . The transgenic plant of  claim 5 , wherein the plant is a monocot. 
     
     
         9 . The transgenic plant of  claim 5 , wherein the plant is a dicot. 
     
     
         10 . The transgenic plant of  claim 5 , wherein the plastid transit peptide encodes the polypeptide selected from the group consisting of SEQ ID NOs:2, 3, 5 and 7. 
     
     
         11 . The transgenic plant of  claim 8 , wherein the monocot is a maize or a sugarcane plant. 
     
     
         12 . The transgenic plant of  claim 9 , wherein the dicot is a soybean or a sugarbeet plant. 
     
     
         13 . A method of stably expressing a heterologous polypeptide in a plant, said method comprising introducing into said plant a DNA construct comprising a first nucleotide sequence encoding a plastid transit peptide from a Glaucocystophyte, wherein said first nucleotide sequence is operably linked to a second nucleotide sequence encoding said heterologous polypeptide. 
     
     
         14 . The method of  claim 13 , wherein the Glaucocystophyte is  Cyanophora.    
     
     
         15 . The method of  claim 13 , wherein the Glaucocystophyte is  Cyanophora paradoxa.    
     
     
         16 . The method of  claim 13 , wherein the plant is a monocot. 
     
     
         17 . The method of  claim 13 , wherein the plant is a dicot. 
     
     
         18 . The method of  claim 13 , wherein the plastid transit peptide encodes the polypeptide selected from the group consisting of SEQ ID NO:2, 3, 5 and 7. 
     
     
         19 . The method of  claim 16 , wherein the monocot is a maize or a sugarcane plant. 
     
     
         20 . The method of  claim 17 , wherein the dicot is a soybean or a sugarbeet plant. 
     
     
         21 . An isolated polypeptide comprising a plastid transit peptide from a Glaucocystophyte operably linked to a heterologous polypeptide. 
     
     
         22 . The isolated polypeptide of  claim 21 , wherein the Glaucocystophyte is  Cyanophora.    
     
     
         23 . The isolated polypeptide of  claim 21 , wherein the Glaucocystophyte is  Cyanophora paradoxa.    
     
     
         24 . The isolated polypeptide of  claim 21 , wherein the plant is a monocot. 
     
     
         25 . The isolated polypeptide of  claim 21 , wherein the plant is a dicot. 
     
     
         26 . The isolated polypeptide of  claim 21 , wherein the plastid transit sequence encodes the polypeptide selected from the group consisting of SEQ ID NOs:2, 3, 5, and 7. 
     
     
         27 . The isolated polypeptide of  claim 24 , wherein the monocot is a maize or a sugarcane plant. 
     
     
         28 . The isolated polypeptide of  claim 25 , wherein the dicot is a soybean or a sugarbeet plant.