A 40-KD PROTEIN FROM VICIA-FABA LEAVES - AN ACTIN OR ACTIN-RELATED PROTEIN

The study of subcellular localization of 40-kD nonribosomal protein, w hich was found earlier in polysome preparations from broad bean (Vicia faba L.) green leaves, showed that most of this protein sedimented at 4000 g. In addition, substantial amounts of this protein were sedimen ted with ''membrane-bound'' and ''free'' polysomes, indicating their t ight association. The 40-kD protein did not cross-react with polyclona l antibodies against ribosome-associated acidic p40 protein from Arabi dopsis thaliana L., although a protein that had cross-reacted with the se antibodies was present in polysomal preparations fi-om both V.faba leaves and etiolated wheat (Triticum aestivum L.) seedlings. The produ cts of 40-kD partial proteolysis of proteins by the proteinase from St aphylococcus aureus V8 were very close but not identical to those of c onventional actin from chicken gizzard.