title: Synthesis of the crystalloid protein complex in vivo in the endosperm of developing castor bean seeds.
abstract: The synthesis of subunit polypeptides of the crystalloid protein complex has been examined in endosperm from developing castor bean (Ricinus communis L. cv Hale) seeds. Pulse-label and -chase studies in vivo have shown that synthesis initially involves the formation of high molecular weight precursors (50 to 60 kilodaltons) comprising peptide-linked acidic and basic polypeptides. Precursor processing involves the posttranslational cleavage of the peptide bond to yield authentic and polypeptides. This processing has a half-life of 35 to 40 minutes and is preceded by a 45- to 60-minute lag period. Both precursor and subunit polypeptides are shown to exhibit similar molecular weight and pI heterogeneity, and this is suggested to be due to the expression of a multigene family.
authors: Plant Physiology Research Group, Biology Department, University of Calgary, Calgary, Alberta, Canada, T2N 1N4.
authors: D J
authors: DJ
authors: Gifford
authors: J D
authors: JD
authors: Bewley