Fad24, a mammalian homolog of Noc3p, is a positive regulator in adipocyte differentiation

J Cell Sci. 2004 Dec 1;117(Pt 25):6217-26. doi: 10.1242/jcs.01546.

Abstract

Adipocyte differentiation is controlled by complex actions involving gene expression and signal transduction. From metaphase to anaphase, peroxisome proliferator-activated receptor gamma, the CCAAT/enhancer-binding protein family and sterol regulatory element-binding protein-1 are known to function as master regulators. However, the mechanism underlying the earliest step, which triggers the initiation of differentiation, remains unknown. In previous reports, we have isolated a number of genes, whose expression increases in the early stage of differentiation in the mouse 3T3-L1 preadipocyte cell line. Here we report the cloning of the full-length cDNA and characterization of an unknown gene isolated previously and named fad24 (factor for adipocyte differentiation 24). Fad24 encodes a protein consisting of 807 amino acids. The deduced amino acid sequence was shown to have a basic leucine zipper motif and a NOC domain. Expression of fad24 was rapidly induced after stimulation with inducers. Furthermore, overexpression of fad24 in NIH-3T3 cells promoted adipogenesis in the presence of a ligand for peroxisome proliferator-activated receptor gamma. FAD24 localizes in the nucleus, especially within nuclear speckles. As the nuclear speckle functions as a nascent transcription and pre-mRNA splicing machinery, there is a possibility that FAD24 functions as one of the components for transcription and/or pre-mRNA splicing and positively regulates adipocyte differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3-L1 Cells
  • Adipocytes / cytology*
  • Adipocytes / metabolism
  • Amino Acid Sequence
  • Anaphase
  • Animals
  • Basic-Leucine Zipper Transcription Factors
  • Blotting, Northern
  • CCAAT-Enhancer-Binding Proteins / metabolism
  • Cell Cycle Proteins
  • Cell Differentiation
  • Cell Nucleus / metabolism
  • Cloning, Molecular
  • DNA, Complementary / metabolism
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation*
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Ligands
  • Metaphase
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • NIH 3T3 Cells
  • Nuclear Proteins / biosynthesis*
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology*
  • Nucleocytoplasmic Transport Proteins / metabolism
  • Nucleocytoplasmic Transport Proteins / physiology*
  • PPAR gamma / metabolism
  • Protein Structure, Tertiary
  • RNA Interference
  • RNA Splicing
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*
  • Sequence Homology, Amino Acid
  • Sterol Regulatory Element Binding Protein 1
  • Subcellular Fractions / metabolism
  • Time Factors
  • Transcription Factors / metabolism

Substances

  • Basic-Leucine Zipper Transcription Factors
  • CCAAT-Enhancer-Binding Proteins
  • Cell Cycle Proteins
  • DNA, Complementary
  • DNA-Binding Proteins
  • Ligands
  • NOC3 protein, S cerevisiae
  • NOC3L protein, human
  • Noc3l protein, mouse
  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • PPAR gamma
  • RNA, Messenger
  • SREBF1 protein, human
  • Saccharomyces cerevisiae Proteins
  • Srebf1 protein, mouse
  • Sterol Regulatory Element Binding Protein 1
  • Transcription Factors
  • Green Fluorescent Proteins