AdipoQ Is a Novel Adipose-specific Gene Dysregulated in Obesity (*)
- From the (1)Dana-Farber Cancer Institute and the Department of Cell Biology and the
- (2)Departments of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
- ¶ To whom correspondence should be addressed: Dana-Farber Cancer Inst., 44 Binney St., Boston, MA 02115. Tel.: 617-632-3567; Fax: 617-632-4655; BruceSpiegelman{at}dfci.harvard.edu.
Abstract
Adipose differentiation is accompanied by changes in cellular morphology, a dramatic accumulation of intracellular lipid and activation of a specific program of gene expression. Using an mRNA differential display technique, we have isolated a novel adipose cDNA, termed adipoQ. The adipoQ cDNA encodes a polypeptide of 247 amino acids with a secretory signal sequence at the amino terminus, a collagenous region (Gly-X-Y repeats), and a globular domain. The globular domain of adipoQ shares significant homology with subunits of complement factor C1q, collagen α1(X), and the brain-specific factor cerebellin. The expression of adipoQ is highly specific to adipose tissue in both mouse and rat. Expression of adipoQ is observed exclusively in mature fat cells as the stromal-vascular fraction of fat tissue does not contain adipoQ mRNA. In cultured 3T3-F442A and 3T3-L1 preadipocytes, hormone-induced differentiation dramatically increases the level of expression for adipoQ. Furthermore, the expression of adipoQ mRNA is significantly reduced in the adipose tissues from obese mice and humans. Whereas the biological function of this polypeptide is presently unknown, the tissue-specific expression of a putative secreted protein suggests that this factor may function as a novel signaling molecule for adipose tissue.
Footnotes
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↵§ Supported by a fellowship from the Sandoz-Dana-Farber drug discovery program.
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↵* This work was funded by a Grant DK42539 from the National Institutes of Health. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵1 The abbreviations used are:
- TNF-α
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tumor necrosis factor α
- DMEM
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Dulbecco's modified Eagle's medium
- PCR
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polymerase chain reaction.
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- Received August 22, 1995.
- Revision received February 22, 1996.
- © 1996 by The American Society for Biochemistry and Molecular Biology, Inc.
