title: The novel gene EGFL9/Dlk2, highly homologous to Dlk1, functions as a modulator of adipogenesis.
abstract: The Dlk1 gene appears to function as a regulator of adipogenesis. Adult Dlk1-deficient mice are obese, but adipose tissue still develops in transgenic mice overexpressing an Fc-dlk1 fusion protein, and neither type of genetically modified mice displays serious abnormalities. It was therefore possible that one yet unidentified gene might either compensate or antagonize for the absence or for overexpression, respectively, of Dlk1 in those animals. In database searches, we found a novel gene, EGFL9, encoding for a protein whose structural features are virtually identical to those of dlk1, suggesting it may function in a similar way. As dlk1 does, the protein encoded by EGFL9/Dlk2 affects adipogenesis of 3T3-L1 preadipocytes and mesenchymal C3H10T1/2 cells; however, it does so in an opposite way to that of dlk1. In addition, expression levels of both genes appear to be inversely correlated in both cell lines. Moreover, enforced changes in the expression of one gene affect the expression levels of the other. Our data suggest that adipogenesis may be modulated by the coordinated expression of Dlk1 and EGFL9/Dlk2.
authors.affiliation: Department of Inorganic and Organic Chemistry and Biochemistry, Medical School, Regional Center for Biomedical Research, University of Castilla-La Mancha, Albacete, Spain.
authors.forename: María-Luisa
authors.initials: ML
authors.lastname: Nueda
authors.forename: Victoriano
authors.initials: V
authors.lastname: Baladrón
authors.forename: José-Javier
authors.initials: JJ
authors.lastname: García-Ramírez
authors.forename: Beatriz
authors.initials: B
authors.lastname: Sánchez-Solana
authors.forename: María-Desamparados
authors.initials: MD
authors.lastname: Ruvira
authors.forename: Samuel
authors.initials: S
authors.lastname: Rivero
authors.forename: María-Angeles
authors.initials: MA
authors.lastname: Ballesteros
authors.forename: Eva-María
authors.initials: EM
authors.lastname: Monsalve
authors.forename: María-José M
authors.initials: MJ
authors.lastname: Díaz-Guerra
authors.forename: María-José
authors.initials: MJ
authors.lastname: Ruiz-Hidalgo
authors.forename: Jorge
authors.initials: J
authors.lastname: Laborda
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D050156:Adipogenesis / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014162:Transfection
chemical_list: D002135:Calcium-Binding Proteins; C512925:Dlk1 protein, mouse; C519681:EGFL9 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins