Determination of the Protein Coding Potential of LncRNA U90926 and its Effect on Adipogenesis
Conference Year
January 2021
Abstract
Long non-coding RNAs (lncRNAs) are a class of non-coding RNA transcripts that have more than 200 nucleotides, a “non-functional” open reading frame (ORF), and poor conservation, but high tissue specificity. In general, lncRNAs have been found to be involved in gene regulation, and recently some lncRNAs were discovered that can produce small but functional peptides. In our laboratory we are investigating the coding potential and function of the novel mouse lncRNA U90926 (U9). We have previously identified this lncRNA of unknown function as highly expressed in activated macrophages in response to an inflammatory stimulus. Others have also shown it to be a potential negative regulator of adipogenesis in vitro. Despite being annotated as lncRNA, U9 has an open reading frame (ORF) that can synthesize a predicted 87 amino acid peptide and contains a signal sequence that directs translation to the lumen of the ER. Through over-expression of tagged U9 ORF and immunocytochemistry, I determined that the U9 peptide is localized to the Golgi apparatus, which is the next step in the secretory pathway. Recent research has also found that U9 expression in 3T3-L1 pre-adipocytes negatively regulated their differentiation into mature adipocytes in vitro. I investigated U9’s role in the regulation of adipose tissue macrophages (ATMs) and adipocytes in vivo. I used a U9 knockout mouse model that our laboratory generated on the C57BL/6 (B6) background using CRISPR-Cas9. I found that when mice were on a high fat diet, U9 knock-out (U9-KO) males gained a lower percentage of weight compared to wild-type (WT) and U9-KO females gained more weight than WT females. Together these results suggest that the U9 ORF produces a peptide that localizes to the Golgi and that U9 plays a role in adipogenesis. Current investigation includes identifying the mode of action of this gene (RNA, peptide, or both) and to confirm its in vivo effects on adipogenesis via possible regulation by adipose tissue macrophages.
Primary Faculty Mentor Name
Dimitry Krementsov
Graduate Student Mentors
Bristy Sabikunnahar
Faculty/Staff Collaborators
Bristy Sabikunnahar (Graduate Student Mentor) and Stella Varnum (Undergraduate Student)
Status
Undergraduate
Student College
College of Agriculture and Life Sciences
Program/Major
Molecular Genetics
Primary Research Category
Biological Sciences
Determination of the Protein Coding Potential of LncRNA U90926 and its Effect on Adipogenesis
Long non-coding RNAs (lncRNAs) are a class of non-coding RNA transcripts that have more than 200 nucleotides, a “non-functional” open reading frame (ORF), and poor conservation, but high tissue specificity. In general, lncRNAs have been found to be involved in gene regulation, and recently some lncRNAs were discovered that can produce small but functional peptides. In our laboratory we are investigating the coding potential and function of the novel mouse lncRNA U90926 (U9). We have previously identified this lncRNA of unknown function as highly expressed in activated macrophages in response to an inflammatory stimulus. Others have also shown it to be a potential negative regulator of adipogenesis in vitro. Despite being annotated as lncRNA, U9 has an open reading frame (ORF) that can synthesize a predicted 87 amino acid peptide and contains a signal sequence that directs translation to the lumen of the ER. Through over-expression of tagged U9 ORF and immunocytochemistry, I determined that the U9 peptide is localized to the Golgi apparatus, which is the next step in the secretory pathway. Recent research has also found that U9 expression in 3T3-L1 pre-adipocytes negatively regulated their differentiation into mature adipocytes in vitro. I investigated U9’s role in the regulation of adipose tissue macrophages (ATMs) and adipocytes in vivo. I used a U9 knockout mouse model that our laboratory generated on the C57BL/6 (B6) background using CRISPR-Cas9. I found that when mice were on a high fat diet, U9 knock-out (U9-KO) males gained a lower percentage of weight compared to wild-type (WT) and U9-KO females gained more weight than WT females. Together these results suggest that the U9 ORF produces a peptide that localizes to the Golgi and that U9 plays a role in adipogenesis. Current investigation includes identifying the mode of action of this gene (RNA, peptide, or both) and to confirm its in vivo effects on adipogenesis via possible regulation by adipose tissue macrophages.