Abstract
11S seed storage protein (globulin) families are produced as precursor in the endoplasmic reticulum (ER), then translocated to storage vacuole and processed into mature form. The family shares conserved bi-cupin structure, and are assembled into trimer form within ER. Amino acid sequence and physical structure of 11S globulins are putative determinants in translocation from ER to storage vacuole (Maruyama et al., 2006). Furthermore, glutelins (11S globulin of rice) show about 40% homology to glycinin (11S globulin of soybean), and are assembled into trimer with glycinin and transported to PB-II in rice seed. It remains unclear whether rice glutelin can be self-assembled or requires chaperons for folding and assembly. We demonstrated by analysis on sucrose density gradient and Blue-Native PAGE that in vivo trimer formation of proglutelin in immature seed and newly synthesized proglutelin can be self-assembled into trimer in vitro.
*Maruyama et al. (2006) Plant cell, 18, 1253
