The novel gene EGFL9/Dlk2, highly homologous to Dlk1, functions as a modulator of adipogenesis.
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.
Nueda
María-Luisa
ML
Department of Inorganic and Organic Chemistry and Biochemistry, Medical School, Regional Center for Biomedical Research, University of Castilla-La Mancha, Albacete, Spain.
Baladrón
Victoriano
V
García-Ramírez
José-Javier
JJ
Sánchez-Solana
Beatriz
B
Ruvira
María-Desamparados
MD
Rivero
Samuel
S
Ballesteros
María-Angeles
MA
Monsalve
Eva-María
EM
Díaz-Guerra
María-José M
MJ
Ruiz-Hidalgo
María-José
MJ
Laborda
Jorge
J
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
D002135:Calcium-Binding Proteins; C512925:Dlk1 protein, mouse; C519681:EGFL9 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins