RRM
2007 Rustbelt RNA Meeting
RRM
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Poster abstracts
Abstract:
Non-coding RNAs (ncRNAs) play significant roles in many crucial aspects of cellular function such as RNA processing, mRNA stability, translation, protein stability and secretion. Despite the rapid progress in our understanding of small non-coding RNAs\' roles, the mechanism of function of larger non-coding RNAs is almost totally unknown. To gain insight into the function of these RNAs we are analyzing the function of BMP/OP- responsive gene (BORG), a 2846 nt non-coding RNA which was originally described in a screen for genes that change their expression in response to bone morphogenic protein 2 (BMP2) in mice.
The 15108 nt-long BORG pre-mRNA contains three exons and two introns, and it also contains a typical poly A signal at the 3’ end. After splicing, the mature message is 2846 nt long and contains regions with homology to B4a and mouse LTR repeat elements. We first ensured that BORG is indeed a non-coding RNA by phylogenetic analysis of the short (<300 bp long) ORFs found in its sequence. All predicted ORFs contained mutations affecting the initiation codon, early frameshift-causing mutations, or early nonsense mutations when mouse and rat BORGs were compared, indicating that the BORG transcript does not have protein-coding potential. We next studied the expression profile of BORG in several embryonic and adult mouse tissue by semi quantitative RT-PCR. BORG has a tissue specific expression pattern, with high expression levels detected in neural tissues, kidney, testis (in adults only) and cardiac tissue (in fetuses only). Efforts are underway to use in situ hybridization to determine the subcellular and organ-level localization of this non-coding RNA.
Borg is located on chromosome 15 in mouse genome, between BAALC (Brain and Acute Leukemia, cytoplasmic) and ATPase, H+ transporting, lysosomal V1 subunit C1 genes. shRNA targeting of BORG in pro-myeloblastic C2C12 mouse cell line does not affect the expression of a number of house keeping genes tested, however, it results in a dramatic repression of the neighboring BAALC gene. BAALC is expressed in neuroectoderm-derived tissues and is highly conserved among mammals. The other neighboring gene of BORG, the ATPase, does not show a significant effect. These data suggest that this non-coding RNA might function, at least partially, through regulation of expression of its neighboring genes, a feature observed in a number of non-coding RNAs. Further, the expression level of BORG shows an increase after serum starvation and heat shock, as determined by semi-quantitative RT-PCR.
To gain more insights into the function of BORG, We aim to discover whether there are human homologue of the mouse BORG gene. Preliminary studies show that the conserved region of this gene is expressed in a tissue specific manner in a few human tissues. Therefore we plan to look for the expression profile of this gene in different human tissues and to also to determine if there is a role in brain development in human for this RNA.
Keywords: large ncRNA
