The travels of mRNAs through all cells large and small.
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Animals↗
Biomedical subjects
Y Oleynikov
Publications and source records attributed to Y Oleynikov.
RNA localization: different zipcodes, same postman?
RNA-localization mechanisms involve specific sequences in the localized RNA and proteins that bind to these sequences and mediate the interaction with cytoskeletal elements. Until recently, it seemed as though two separate types of mechanisms were operating for mRNA localization--involving interaction with either microtubules or actin microfilaments. However, it is now clear that some of the protein components involved in mRNA localization can participate in both microtubule- and actin-dependent localization pathways. This, combined with new evidence for evolutionary conservation of some of these proteins, suggests a previously unanticipated uniformity in mRNA-localization mechanisms.
Actin Cytoskeleton↗
Characterization of a beta-actin mRNA zipcode-binding protein.
Localization of beta-actin mRNA to the leading edge of fibroblasts requires the presence of conserved elements in the 3' untranslated region of the mRNA, including a 54-nucleotide element which has been termed the "zipcode" (E. Kislauskis, X. Zhu, and R. H. Singer, J. Cell Biol. 127:441-451, 1994). In order to identify proteins which bind to the zipcode and possibly play a role in localization, we performed band-shift mobility assays, UV cross-linking, and affinity purification experiments. A protein of 68 kDa was identified which binds to the proximal (to the coding region) half of the zipcode with high specificity (ZBP-1). Microsequencing provided unique peptide sequences of approximately 15 residues each. Degenerate primers corresponding to the codons derived from the peptides were synthesized and used for PCR amplification. Screening of a chicken cDNA library resulted in isolation of several clones providing a DNA sequence encoding a 67.7-kDa protein with regions homologous to several RNA-binding proteins, such as hnRNP E1 and E2, and with consensus mRNA recognition motif with RNP1 and 2 motifs and a putative REV-like nuclear export signal. Antipeptide antibodies were raised in rabbits which bound to ZBP-1 and coimmunoprecipitated proteins of 120 and 25 kDa. The 120-kDa protein was also obtained by affinity purification with the RNA zipcode sequence, along with a 53-kDa protein, but the 25-kDa protein appeared only in immunoprecipitations. Mutation of one of the conserved sequences within the zipcode, an ACACCC element in its proximal half, greatly reduced its protein binding and localization properties. These data suggest that the 68-kDa ZBP-1 we have isolated and cloned is an RNA-binding protein that functions within a complex to localize beta-actin mRNA.
Actins↗