Sequence-specific, Golgi-dependent vacuolar targeting of castor bean 2S albumin.
The targeting of the castor bean (Ricinus communis) 2S albumin precursor has been investigated by expressing cDNA in transformed tobacco (Nicotiana tabacum) leaf cells and by following biosynthesis in the native tissue. Correct targeting in both tissues was accompanied by processing of the precursor. Delivery to vacuoles was sensitive to brefeldin A (BFA) treatment in both tissues and to perturbation of COPII function in tobacco, supporting the view that transport through the Golgi is required. The targeting signal for this Golgi-dependent routing lies within the propeptide of the first heterodimer of proalbumin. This propeptide directed a normally secreted reporter protein to the vacuoles of tobacco cells in a Golgi-dependent manner in vivo, unless a critical Leu residue was mutated, supporting the view that a sequence-specific signal was needed to target a seed storage protein to the vacuoles of a vegetative cell.
Brown
Joanna C
JC
Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
Jolliffe
Nicholas A
NA
Frigerio
Lorenzo
L
Roberts
Lynne M
LM
D055516:2S Albumins, Plant; D052179:Antigens, Plant; D001483:Base Sequence; D020126:Brefeldin A / Q000494:pharmacology; D002367:Ricinus communis / Q000235:genetics*; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D006056:Golgi Apparatus / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics; D021381:Protein Transport; D011523:Protoplasts / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics; D014162:Transfection; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism
D055516:2S Albumins, Plant; C541551:2S storage protein, Ricinus communis; D052179:Antigens, Plant; D017931:DNA Primers; D004275:DNA, Ribosomal; D010940:Plant Proteins; D011994:Recombinant Proteins; D020126:Brefeldin A