Abstract:
Directional transport of specific mRNAs is of primary biological relevance. In Xenopus oocytes, mRNA localization to
the vegetal pole is important for germ layer formation and germ cell development. Using a biochemical approach, we
identified Xenopus Elr-type proteins, homologs of the Hu/ELAV proteins, as novel components of the vegetal mRNA
localization machinery. They bind specifically to the localization elements of several different vegetally localizing
Xenopus mRNAs, and they are part of one RNP together with other localization proteins, such as Vg1RBP and
XStaufen 1. Blocking Elr-type protein binding by either localization element mutagenesis or antisense morpholino
oligonucleotide-mediated masking of their target RNA structures, as well as overexpression of wild type and mutant
ElrB proteins, interferes with vegetal localization in Xenopus oocytes.