The maize brittle 1 gene encodes amyloplast membrane polypeptides

Planta. 1995;196(3):477-84. doi: 10.1007/BF00203647.


A chimeric protein, formed of 56 amino acids from the carboxy terminus of the maize (Zea mays L.) wild-type Brittle1 (Bt1) protein fused to the glutathione-S-transferase gene, was synthesized in Escherichia coli, and used to raise antibodies. Following affinity purification, the antibodies recognized a set of 38- to 42-kDa proteins in endosperm from wild-type Bt1 plants, as well as from brittle2, shrunken2 and sugary1 plants, but not in mutant bt1 endosperm. Bt1 proteins were not detected with the preimmune antibodies. A low level of Bt1-specific proteins was detected at 10 d after pollination (DAP) and increased to a plateau at 16 DAP. At the same time, the ratio of slow- to fast-migrating forms of the protein decreased. During endosperm fractionation by differential centrifugation and membrane sedimentation in sucrose gradients, the Bt1 proteins co-purified with the carotenoid-containing plastid membranes. They were localized to amyloplasts by electron-microscopic immunocytochemistry; most of the signal was detected at the plastid periphery. These results are consistent with predictions made from the deduced amino-acid sequence and previous in-vitro experiments that the bt1 locus encodes amyloplast membrane proteins.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antibodies
  • Antibody Specificity
  • Cell Fractionation
  • Escherichia coli
  • Gene Expression
  • Membrane Proteins / genetics*
  • Membrane Proteins / immunology
  • Microscopy, Electron
  • Plant Proteins / genetics*
  • Plant Proteins / immunology
  • Recombinant Fusion Proteins / genetics
  • Zea mays / genetics*
  • Zea mays / ultrastructure


  • Antibodies
  • Membrane Proteins
  • Plant Proteins
  • Recombinant Fusion Proteins