Poster abstracts

Poster number 53 submitted by Paula Bubulya

Dynamics and Cellular Functions of Btf

Paula Bubulya (Department of Biological Sciences, Wright State University), Zhihui Deng (Department of Neuroscience, Cell Biology and Physiology, Wright State University), Athanasios Bubulya (Department of Biological Sciences, Wright State University)

Abstract:
Bcl-2-like transcription factor (Btf) is a novel nuclear speckle protein identified in a proteomic analysis of purified nuclear speckles. Btf exhibits a subnuclear localization that is unique compared to that of other nuclear speckle proteins. Immunofluorescence localization of Btf shows that it is not completely coincident with other nuclear speckle proteins, and it is not largely enriched in the “core” of the speckles. Rather, Btf is enriched in regions near the periphery of nuclear speckles. While nuclear speckles are sites of enrichment for pre-mRNA processing factors, most transcription and pre-mRNA processing occurs outside of the speckles. In addition to the peripheral nuclear speckle localization, Btf is also found in a punctate nucleoplasmic distribution that is similar to the foci seen when transcription sites are labeled by bromo-UTP incorporation. Btf is not yet characterized with regard to the function of this novel localization, but it is important to determine if the localization corresponds with transcription sites. Our data shows that Btf can accumulate at an activated reporter gene locus. We hypothesize that Btf plays a role in transcription and/or pre-mRNA splicing, and that the novel Btf localization reflects this function.

Keywords: transcription, splicing, nuclear speckles