Two Closely Related Wheat Storage Proteins Follow a Markedly Different Subcellular Route in Xenopus laevis Oocytes

Rachelle Simon, Yoram Altschuler, Regina Rubin, Gad Galili
1990 The Plant Cell  
O0 a-Gliadins and y-gliadins are two closely related wheat storage proteins that evolved from a common ancestral gene. However, synthesis of a-gliadins and y-gliadins in Xenopus laevis oocytes revealed striking differences in their subcellular routing. The major portion of a-gliadin accumulated inside the oocyte, whereas most of the ygliadin was secreted. Disruption of the Golgi apparatus by monensin revealed that the major part of secretion of ygliadin is Golgi mediated. The difference in the
more » ... difference in the subcellular route between a-gliadin and y-gliadin may be attributed to differential transport from the endoplasmic reticulum to the Golgi apparatus, a process that is generally the ratelimiting step in protein secretion. Coinjection of the two mRNAs had no effect on their routing, indicating no interaction between them. Our results support the hypothesis that subcellular transport of gliadins in wheat endosperm occurs in two separate routes; one is Golgi mediated, and the other is not. We also show that the subcellular transport may be markedly affected by small structural variations within closely related storage proteins.
doi:10.2307/3869329 pmid:12354972 fatcat:uept5pwk3vdz3ow2fs4ljmtodi