No description available.

Intra-axonal protein synthesis is important for the proper wiring of the nervous system and can have restorative or pathogenic effects in response to nerve injury and neurodegenerative stimuli. The set of axonally translated transcripts, the axonal translatome, is regulated through the control of mRNA localization, stability, and translation. Targeting the axonal translatome could result in the development of novel therapies for the treatment of neurological disorders. Yet, there are gaps in our understanding of the selective mechanism regulating the specific localization of mRNAs into axons. Currently, axonal localization of transcripts is understood to be controlled by the presence of sequence elements that direct axonal transport. In an attempt to identify novel localization motifs, I found that a well-known motif corresponding to the Pumilio Binding Element (PBE) is significantly depleted in axonally enriched mRNAs. Moreover, I found this element to be highly informative of axonal mRNA localization and translation across different neuronal types and developmental stages suggesting that it is a highly conserved regulatory motif. I found Pum2 neuronal expression and subcellular localization to be highly consistent with the way the PBE predicts mRNA regulation. I then demonstrated that interfering with Pum2 function results in increased axonal localization of PBE containing mRNAs. Finally, Pum2 downregulation was associated with gross defects in axonal outgrowth, branching, and regeneration. Altogether, this data suggests that Pum2 regulates axonal mRNA localization through an exclusion mechanism that is important during neuronal development.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 138-149). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Kirk J. Cymmek, Dept. of Biological Sciences. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 102-112). Available also in a digital version from Dissertation Abstracts.

Not available / text

No description available.

The localization, trafficking and regulation of messenger ribonucleic acids (RNA) and viral RNA play crucial roles in cellular homeostasis and disease pathogenesis. In recent years biochemical and molecular biology methods used to study RNA function have made several important advances in the areas of RNA interference, expression of transgenes, and the sequencing of transcriptomes. In contrast, current technologies for imaging RNA in live cells remain in limited use. Previous studies of RNA localization and dynamics have relied primarily on the expression of a reporter RNA and a fluorescent protein fusion that binds to aptamer sequences in the expressed RNA. While these plasmid based systems offer methodological flexibility, there remains a need to develop methods to image native, non-engineered RNA as plasmid derived RNAs may not have the same regulatory elements (3'UTR and introns) or copy number as the native RNA. Additionally, viral pathogenesis is often sensitive to the size and sequence of their genomic RNA and may not be suitable for study using engineered systems. We sought to develop and validate a new method for imaging native, non-engineered RNA with single molecule-sensitivity. These probes have four important properties. They are modular, compatible with fixation and immunostaining, bind quickly and specifically to targets, and do not interfere with RNA function. We built upon the technique of delivering exogenous, linear probes that bind to their target by Watson-Crick base pairing. The probes are multiply labeled and tetramerized to increase their brightness. To validate the probes, targeting and utility was demonstrated in two model systems: beta-actin mRNA to show targeting of an endogenous target and the genomic RNA of human respiratory syncytial virus to show targeting of a viral RNA target. All video files are in QuickTime format.

No description available.