title: Transformer 2β homolog (Drosophila) (TRA2B) regulates protein kinase C δI (PKCδI) splice variant expression during 3T3L1 preadipocyte cell cycle.
abstract: Obesity is characterized by adipocyte hyperplasia and hypertrophy. We previously showed that PKCδ expression is dysregulated in obesity (Carter, G., Apostolatos, A., Patel, R., Mathur, A., Cooper, D., Murr, M., and Patel, N. A. (2013) ISRN Obes. 2013, 161345). Using 3T3L1 preadipocytes, we studied adipogenesis in vitro and showed that expression of PKCδ splice variants, PKCδI and PKCδII, have different expression patterns during adipogenesis (Patel, R., Apostolatos, A., Carter, G., Ajmo, J., Gali, M., Cooper, D. R., You, M., Bisht, K. S., and Patel, N. A. (2013) J. Biol. Chem. 288, 26834-26846). Here, we evaluated the role of PKCδI splice variant during adipogenesis. Our results indicate that PKCδI expression level is high in preadipocytes and decreasing PKCδI accelerated terminal differentiation. Our results indicate that PKCδI is required for mitotic clonal expansion of preadipocytes. We next evaluated the splice factor regulating the expression of PKCδI during 3T3L1 adipogenesis. Our results show TRA2B increased PKCδI expression. To investigate the molecular mechanism, we cloned a heterologous splicing PKCδ minigene and showed that inclusion of PKCδ exon 9 is increased by TRA2B. Using mutagenesis and a RNA-immunoprecipitation assay, we evaluated the binding of Tra2β on PKCδI exon 9 and show that its association is required for PKCδI splicing. These results provide a better understanding of the role of PKCδI in adipogenesis. Determination of this molecular mechanism of alternative splicing presents a novel therapeutic target in the management of obesity and its co-morbidities.
authors.affiliation: Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612.
authors.forename: Rekha S
authors.initials: RS
authors.lastname: Patel
authors.affiliation: James A. Haley Veterans Hospital and University of South Florida, Tampa, Florida 33612.
authors.forename: Gay
authors.initials: G
authors.lastname: Carter
authors.affiliation: Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612; James A. Haley Veterans Hospital and University of South Florida, Tampa, Florida 33612.
authors.forename: Denise R
authors.initials: DR
authors.lastname: Cooper
authors.affiliation: Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612.
authors.forename: Hercules
authors.initials: H
authors.lastname: Apostolatos
authors.affiliation: Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612; James A. Haley Veterans Hospital and University of South Florida, Tampa, Florida 33612. Electronic address: iketa.Patel@va.gov.
authors.forename: Niketa A
authors.initials: NA
authors.lastname: Patel
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology; D050156:Adipogenesis; D017398:Alternative Splicing; D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D005786:Gene Expression Regulation; D051379:Mice; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D000068103:Serine-Arginine Splicing Factors
chemical_list: D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C100345:Tra2b protein, mouse; D000068103:Serine-Arginine Splicing Factors; D051745:Protein Kinase C-delta
keywords: Adipogenesis; Alternative Splicing; Cell Cycle; Obesity; PRKCD; Protein Kinase C (PKC); TRA2B