title: Prosomes exist in plant cells too.
abstract: A 19S particle was purified from tobacco (Nicotiana rustica) leaf cells. Its density was determined as 1296 g/cm3 in Cs2SO4-DMSO gradients, indicating the presence of RNA and protein. Polyacrylamide gel electrophoresis (PAGE) revealed eight distinct proteins in the range of 20-30 kD and RNA in the range of 70-80 nucleotides. Electron microscopic examination showed the same raspberry-shaped structure with a central depression as described for prosomes. We conclude that tobacco 19S particles represent small cytoplasmic complexes, possessing biochemical and structural characteristics similar to the hither-to known prosomes of animal cells.
mesh_terms: D002499:Centrifugation, Density Gradient; D008854:Microscopy, Electron; D008970:Molecular Weight; D010940:Plant Proteins / Q000032:analysis; D010944:Plants / Q000032:analysis* / Q000648:ultrastructure; D010947:Plants, Toxic; D012261:Ribonucleoproteins / Q000032:analysis*; D017411:Ribonucleoproteins, Small Nuclear; D014026:Nicotiana
chemical_list: D010940:Plant Proteins; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear