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A proline‐rich protein binds to the localization element of Xenopus Vg1 mRNA and to ligands involved in actin polymerization
Author(s) -
Zhao Weimeng,
Jiang Can,
Kroll Todd T.,
Huber Paul W.
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.9.2315
Subject(s) - biology , xenopus , actin , messenger rna , polymerization , microbiology and biotechnology , biochemistry , gene , polymer , chemistry , organic chemistry
A 340 nucleotide element within the 3′ untranslated region of Vg1 mRNA determines its localization to the vegetal cortex of Xenopus oocytes. To identify protein factors that bind to this region, we screened a cDNA expression library with an RNA probe containing this sequence. Five independent isolates encoded a protein (designated Prrp for p roline‐ r ich R NA binding p rotein) having two RNP domains followed by multiple polyproline segments. Prrp and Vg1 mRNAs are co‐localized to the vegetal cortex of stage IV oocytes, substantiating an interaction between the two in vivo . Prrp also associates with VegT mRNA, which like Vg1 mRNA uses the late localization pathway, but not with Xcat‐2 or Xwnt‐11 mRNAs, which use the early pathway. The proline‐rich domain of Prrp interacts with profilin, a protein that promotes actin polymerization. Prrp can also associate with the EVH1 domain of Mena, another microfilament‐associated protein. Since the anchoring of Vg1 mRNA to the vegetal cortex is actin dependent, one function of Prrp may be to facilitate local actin polymerization, representing a novel function for an RNA binding protein.