Adipocyte P2 gene: developmental expression and homology of 5'-flanking sequences among fat cell-specific genes.
We have isolated the mouse gene encoding adipocyte P2, aP2, the differentiation-dependent adipocyte protein homologous to myelin P2. The aP2 gene is present in a single copy in the mouse and is present in single or few copies in species from human to Drosophila. The entire gene spans 4 kilobases and consists of four exons encoding 25, 57, 34, and 16 amino acids; the overall exon structure is similar to the gene encoding liver fatty acid binding protein. A plasmid vector was constructed containing the entire aP2 gene with flanking sequences, modified by linker insertion. When this gene is stably introduced into 3T3-F442A cells, it is expressed only upon adipose differentiation, with a time course of induction very similar to that of the endogenous aP2 gene. We have compared the DNA sequence of the 5'-flanking region of the aP2 gene to the promoter regions of two other genes activated during adipocyte differentiation, glycerol-3-phosphate dehydrogenase and adipsin, and find a 13-base region of homology (Formula: see text) present in multiple copies in the 5'-flanking region of each gene. An adjacent 15-base sequence is present only in glycerol-3-phosphate dehydrogenase and aP2 genes. Both of these elements share homology with putative viral enhancer core sequences. These results indicate that the aP2 gene contains sequence information necessary for differentiation-dependent expression in fat cells; common elements shared by adipocyte-specific genes may play a role in this process.
D000273:Adipose Tissue / Q000166:cytology / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D002454:Cell Differentiation; D003001:Cloning, Molecular; D011416:Complement Factor D; D010450:Endopeptidases / Q000235:genetics; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics; D051379:Mice; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D012697:Serine Endopeptidases; D014018:Tissue Distribution
D002352:Carrier Proteins; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D005993:Glycerolphosphate Dehydrogenase; D010450:Endopeptidases; D012697:Serine Endopeptidases; C493488:CFD protein, human; D011416:Complement Factor D; C493491:complement factor D, mouse