Conserved and clustered RNA recognition sequences are a critical feature of signals directing RNA localization in Xenopus oocytes

• Published in: Mechanisms of development Vol. 121; no. 1; pp. 101 - 109
• Main Authors: Lewis, Raymond A., Kress, Tracy L., Cote, Colette A., Gautreau, Denise, Rokop, Megan E., Mowry, Kimberly L.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 2004
• Subjects: 3' Untranslated Regions - metabolism; Animals; Base Sequence; Conserved Sequence; Female; Heterogeneous-Nuclear Ribonucleoproteins - metabolism; Molecular Sequence Data; Oocytes - metabolism; Polypyrimidine Tract-Binding Protein - metabolism; RNA - metabolism; RNA-binding protein; RNP; Vg1; Vg1RBP/vera; VgRBP60/hnRNP I; Xenopus; Xenopus Proteins - metabolism; Vg1; RNA-binding protein; Vg1RBP/vera; VgRBP60/hnRNP I; RNP
• ISSN: 0925-4773; 1872-6356
• DOI: 10.1016/j.mod.2003.09.009

Although it is widely regarded that the targeting of RNA molecules to subcellular destinations depends upon the recognition of
cis-elements found within their 3′ untranslated regions (UTR), relatively little is known about the specific features of these
cis-sequences that underlie their function. Interaction between specific repeated motifs within the 3′ UTR and RNA-binding proteins has been proposed as a critical step in the localization of Vg1 RNA to the vegetal pole of
Xenopus oocytes. To understand the relative contributions of repeated localization element (LE) sequences, we used comparative functional analysis of Vg1 LEs from two frog species,
Xenopus laevis and
Xenopus borealis. We show that clusters of repeated VM1 and E2 motifs are required for efficient localization. However, groups of either site alone are not sufficient for localization. In addition, we present evidence that the
X. borealis Vg1 LE is recognized by the same set of RNA-binding proteins as the
X. laevis Vg1 LE and is capable of productive interactions with the
X. laevis transport machinery as it is sufficient to direct vegetal localization in
X. laevis oocytes. These results suggest that clustered sets of
cis-acting sites within the LE direct vegetal transport through specific interactions with the localization machinery.